Knowledge Base

Sort by

CodeTwo Reseller Panel: frequently asked questions (FAQ)

This article contains a list of questions frequently asked by CodeTwo partners and resellers. How to place an order? How can I calculate the product price? Can I order multiple products at the same time? Can I transfer a license (ID:810)

What happens to my emails after migration if the source and target domains are different

Problem: You've just completed the migration of mailboxes with CodeTwo migration tools and now you need to reply to emails and appointments. However, since the target domain is different from the source one, your replies are sent from  (ID:742)

Migrating default Outlook folders

Problem: You are migrating data between two environments that use different display languages, e.g. English is used on the source server and German on the target one. Once the migration finishes, you notice that the contents of the Inbox (ID:712)

How to set up DNS records properly for a migration

Problem: How to set up DNS records for a source and target domains, to make the cross-domain migration flawless. Solution: Please be aware that steps below are for cross-domain migration and assume both domains should be resolvable (ID:524)

Missing MAPI profile

Problem: You have created a MAPI profile but cannot see it e.g. in MFCMAPI. Solution: MAPI profiles are visible only to users for which they were created. If you created a MAPI profile for a mailbox of, let us say User-A, its MAP (ID:522)

Free/Busy status migration

Problem: Does CodeTwo Exchange Migration or CodeTwo Office 365 Migration software migrate Free/Busy status? Solution: The Free/busy info is a feature of MS Exchange Server provided by Availability Service. This is not something  (ID:354)

Does CodeTwo migration software support delta pass migrations?

Problem: Does CodeTwo Exchange Migration or CodeTwo Office 365 Migration support "delta pass" migrations? Solution: Our migration software has a built-in feature that checks if an already migrated mailbox received any new items (ID:333)

How to find the license key in CodeTwo software

Problem: You need to find the license key for your CodeTwo software. Solution: CodeTwo applications are activated to the full version by entering a 25-character license key that you receive once the order is paid for. Finding th (ID:167)

Troubleshooting server connection

If you configure the EWS connection to a source/target Exchange Server, the first action (test) performed by the program is always Check connection to Exchange Server, as shown in Fig. 1. below. During this operation, the software tries t


CodeTwo Exchange Migration lets you migrate your company's mailboxes and public folders located on on-premises Exchange servers (all versions are supported) or in Office 365 / Office 365 Germany. The program works equally great for m

Migration walkthrough

The documentation presented here applies to specific migration types and will guide you through the whole process from A to Z. In this section, we explain the preparation of the environment for migration, provide the steps for successful

Cross-forest migration from Exchange 2010 to Exchange 2019/2016/2013

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo

Supported platforms and system requirements

The tables below show the program's requirements, necessary for its proper operation, and the list of supported platforms. Software components The program consists of two main components: CodeTwo Exchang

Connecting to a source IMAP server

Once the installation of CodeTwo Exchange Migration is finished, you have to choose a source environment from which the data will be pulled and migrated to selected mailboxes on target Exchange Server. This article describes how to connec

Additional configuration information

CodeTwo Exchange Migration offers additional options that improve the migration process and let you take control of the mailbox items that will be migrated. These options are available as steps in the migration job wizard or the server con

Matching mailboxes

For the migration to occur, each source mailbox needs to be paired with a target mailbox. The purpose of the matching process is to create associations between source and target mailboxes. The matching process takes place in the Match ma


CodeTwo Exchange Migration is a tool designed to migrate source mailboxes and public folders to the chosen target location. Unlike any other software of this kind, this program performs the simplified migration, which doesn't need any extra

Cross-forest migration from Exchange 2013 to Exchange 2019/2016

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo

Cutover migration

In this article, you will learn about what the cutover migration is, how to perform it in CodeTwo Exchange Migration, and what are the most common use cases for this migration type. What is a cutover migration? How to perform the cu

Connecting to a source on-premises Exchange server

Once the installation of CodeTwo Exchange Migration is finished, you have to choose a source environment from which the data will be pulled and migrated to selected mailboxes on target Exchange Server. This article describes how to connec

Troubleshooting source Exchange Server connectivity

This article describes the Check connection to Exchange Server action of the source connection wizard. When this action is performed, the program uses the administrator account (provided in the previous step of the wizard) to create a MAPI

Staged migration

This article describes how to use CodeTwo Exchange Migration to migrate all your data in two stages. Use the links below to learn more about: characteristic features of the staged migration how to perform the staged migration  us

Configuring a migration job

After you have defined the source connection, you can continue to configure a migration job. A simple wizard will help you define all crucial aspects of the migration, for example selecting a target server, range of mailboxes and necessa

Dashboard and Jobs

The Administration Panel of CodeTwo Exchange Migration consists of the following tabs: Dashboard - allows you to get a basic overview of the program status. You can check the progress of your migrations, activate the program or verif

Connecting to a target Exchange server

Once you installed CodeTwo Exchange Migration and configured a source environment, it is time to create a connection to your target Exchange server. Info The program uses Exchange Web Services (EWS) to connect to a target Microsof

Installation process

Before installing CodeTwo Exchange Migration, you need to decide on which machine you want to install it. The main factor you should take into consideration is your migration source. In migrations from on-premises Exchange Server, the p

Hybrid migration

A hybrid environment is where your on-premises Exchange server is synced with Office 365. CodeTwo migration software can be successfully used for scenarios that involve migrating data from or to such an environment. What is a hybrid m

Migration types

CodeTwo migration software supports most common migration types: cutover, staged and hybrid. Simply configure the migration job accordingly, and the program will do the rest for you. In case you're not sure which type is best suited for y

Migration from IMAP source to Exchange 2019/2016/2013

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo


The licensing model of CodeTwo Exchange Migration is based on the total number of source mailboxes that will be migrated. Each migrated mailbox consumes one license. Regardless of the number of licenses that you purchased, you will only rec

Migration speed

In certain situations, users might notice that process of both gathering and uploading data takes longer than expected considering the network bandwidth. Multiple factors may impact speed of the migration. Where to install First of a


You need to activate CodeTwo Exchange Migration after the trial license has expired. Follow the links below to learn how to: Activate the program for the first time Activate the program after an upgrade Update the number of availa

Cross-forest migration from Exchange 2007 to Exchange 2019/2016/2013

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo


The scheduler feature (Fig. 1.) allows you to set the time frames for the migration. With this feature,you can plan the migration ahead and choose the most convenient times for running the migration job. Since migration is often extremely t

Installation overview

This section includes essential information regarding the installation of the program in your environment. Navigate through the articles listed below and learn how to: Install the program Update or upgrade and what is the differe


The Reports feature allows you to track the progress of your migrations. To create a new, up-to-date report of the desired range, use the Reports section (Fig. 1.) on the ribbon, available on the Jobs tab. The program allows you generat

Additional migration options for mailboxes

The program offers some additional migration settings for individual mailboxes. To access them, open the JOBS tab and select a migration job from the menu on the left. Choose any mailbox from the list (Fig. 1.) and right-click it to see t

Management roles

CodeTwo Exchange Migration takes advantage of the Role Based Access Control (RBAC) permission model to connect to both source and target on-premises Exchange servers via EWS. RBAC enables assigning different roles to users in order to maint

How to

This section includes step-by-step instructions on how to configure and start a migration job. Before rushing to migration, make sure that you understand how the software works, your environment meets all the requirements, and the softwar

Cross-forest migration from Exchange 2003 to Exchange 2019/2016/2013

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo

Cross-forest migration from Office 365 to Exchange 2019/2016

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo

EWS source/target connectivity

Exchange Web Services (EWS) are used by the program to connect to: source Exchange Server - this method should be used for connections to Exchange 2010 with SP1 or later (for connections to Exchange versions earlier than 2010 SP1, M

Connecting to source Office 365

Once the installation of CodeTwo Exchange Migration is finished, you need to choose a source environment from which the data will be pulled and migrated to selected mailboxes in target Exchange Server. This article describes how to connect

Target Exchange server's name vs. its IP address

On the first screen of the Target server connection wizard, you can decide to configure the connection manually. In such a case, we recommend using the name of the server instead of its IP. If, however, you need to use the IP address of th

Delta migration explained

After you configure and start a migration job, CodeTwo Exchange Migration performs a full migration of the selected data from the source server to the target one. Once the full migration is finished, you can use the Rescan feature that scan

Troubleshooting View-Only Configuration role assignment

When configuring the connection to on-premises Exchange server, the connection wizard checks if the provided admin account is assigned the View-Only Configuration role. If the role is missing, the Configuration step fails (Fig. 1.), as the

Troubleshooting Graph API connectivity

This article covers the most common errors related to Graph API connectivity.  Code: Authorization_RequestDenied Message: Insufficient privileges to complete the operation. CodeTwo Exchange Migration doesn't have the necessary per


The most common errors that you might encounter when using CodeTwo Exchange Migration depend on your connection method. Use the links below to learn more. Troubleshooting EWS connectivity (Exchange Server & Office 365) Troubleshoo

Troubleshooting application authentication

When configuring a connection to Office 365, the program attempts to authenticate itself with your Azure Active Directory. If it fails to do so, you will receive the following notification (Fig. 1.): Fig. 1. Failure to authenticate C

How to update or upgrade and what is the difference

The version number The program version is always visible at the very top of the main window of the program. It consists of 4 numbers separated by dots, e.g., following the pattern below: [major].[minor].[maintenance].[build]

Log files

CodeTwo Exchange Migration generates various diagnostic data for all its components. All this data is kept together within the software's subfolder in the %ProgramData% folder along with some configuration and statistics files. Sending

IMAP source connectivity

While configuring an IMAP connection, the application attempts to contact the desired server using IMAP protocol. To connect properly to an IMAP server, the program needs the following information: Host name, provided either as an IP

Upgrade to version 3.x

The upgrade is free of charge for all clients who already own a valid license key for version 2.x. or 1.x.  New clients are welcome to purchase a license key on the product’s website. Important The license key version needs to

First steps

First time using the program? Here are some useful links: Supported platforms and requirements – see the technical specifications required to use the software. Installation process – find out how to install CodeTwo Exchange Migr

Managing server connections

Once you have configured the connection to your source and target environment, these connections will be shown on the Administration Panel's Dashboard tab, on the Defined source server connections or Defined target server connections cards,

Troubleshooting ApplicationImpersonation role assignment

When configuring the connection to a source on-premises Exchange server, the connection wizard checks if the provided admin account is assigned the ApplicationImpersonation role. If the role is missing, the Configuration step fails (Fig. 1.

Troubleshooting Public Folders migration

When configuring the connection to a target server, the connection wizard checks if the provided admin account is assigned the Public Folders role. If the role is missing, you receive a warning message. The text of the warning message, as

Troubleshooting EWS connectivity (Office 365)

CodeTwo Exchange Migration attempts to connect to EWS (Exchange Web Services) during the Configuration step of the source server connection wizard. If the connection cannot be established, you will get the following error message: Fig.

Troubleshooting View-Only Recipients role assignment

When configuring the connection to a target server, the connection wizard checks if the provided admin account is assigned the View-Only Recipients role. If the role is missing, the Configuration step fails (Fig. 1.), as the program is not

Understanding CodeTwo Exchange Migration

The articles below include conceptual descriptions of all features of the program. It is recommended that you familiarize yourself with them so you know the software mechanics and the idea our developers had in mind when creating it. B

Troubleshooting the source Exchange Server administrator's group membership

This article describes the Check group membership action of the source MAPI connection wizard. When this action is performed, the program checks if the administrator (provided in the previous step of the wizard) is a member of a required gr

Troubleshooting Data Provider service configuration

This article describes the Configure data provider service action of the source MAPI connection wizard. When this action is performed, the program configures the Data Provider Service. The service uses the MAPI profile of the defined adm

Troubleshooting application registration

If you choose the Automatic registration option when configuring a source Office 365 connection in the program, the connection wizard attempts to register CodeTwo Exchange Migration in your Azure Active Directory. If the attempt fails in

MAPI source connectivity

MAPI is one of the available methods of connecting to a source Exchange server. You need to choose the MAPI protocol if you connect to Exchange 2003, 2007 or 2010 without SP1. Important The program currently allows creating only o

Program's components

CodeTwo Exchange Migration consists of the following components: Data Provider Service and Administration Panel. To provide you with maximum safety, there are no CodeTwo agents on the intermediary, third-party servers. CodeTwo Exchange M

Trial version

The trial version of CodeTwo Exchange Migration works for 30 days for an unlimited number of mailboxes. However, you can only migrate up to 10 items of any type (emails, contacts, tasks, meetings etc.) from each mailbox, including public fo

How to uninstall CodeTwo Exchange Migration

To uninstall CodeTwo Exchange Migration from your machine, follow these steps:  Open Control Panel in Windows. Click (Programs >) Programs and Features. Find CodeTwo Exchange Migration on the list, right-click it and select Uni

Office 365 connectivity

To connect with Office 365, CodeTwo Exchange Migration needs to be registered in the Azure AD of each tenant that is used in the migration process. Once registered, the application uses Microsoft Graph and Exchange Web Services to access ma

Refreshing email addresses

To perform a successful migration with CodeTwo Exchange you need to, at least, connect to your source and target servers, select mailboxes that you want to migrate and match them with mailboxes residing on your target server. However, each

Reinstall or move to a different machine

Sometimes you may need to reinstall the program or even to move it to a different computer. See below how to do that. Reinstallation Reinstallation of the software is rarely required. However, it may happen that it will be recommende

Monitoring and diagnostics

CodeTwo Exchange Migration provides multiple ways of monitoring the software state, behavior and diagnosing problems: Dashboard and Jobs - the Administration Panel, which consists of Dashboard and Jobs tabs, serves as command and co

Troubleshooting permission to create new mailboxes

When configuring the connection to a target server, the connection wizard checks if the provided admin account is assigned the Mail Recipient Creation and Mail Recipients roles. If they are missing, the following warning messages are shown

Cross-forest migration from Exchange 2016 to Exchange 2019/2016

I. Pre-migration activities Before you install and configure CodeTwo Exchange Migration, make sure that your environment (both the source and target server) is prepared for migration and that you meet the system requirements. Belo


Your feedback is very important to us. It has continuously helped us develop better applications and we strongly encourage you to send us your concerns and suggestions about new and existing features. Your opinion shapes new functionalitie

Why do I need this product?

CodeTwo Exchange Migration takes the most grueling part of a server migration or upgrade – the move of users’ mailboxes and public folders – off your back. A configuration wizard guides you smoothly through the migration job setup and the Automatch feature pairs source and target mailboxes. After these steps, simply click Start and the program automatically performs a direct migration of the mailboxes you selected to the target environment (without deleting items on the source server side).

Our biggest advantages over the competition or tools provided by Microsoft are:

  • direct migrations from any Exchange Server (including Small Business Servers) to Exchange 2019, 2016, 2013 or 2010 (no need for double-hop migrations or migrating data in batches);
  • migrations from Office 365 (Microsoft 365) organizations to on-premises environments;
  • radically simplified migrations to new domains or forests;
  • easy public folder migrations;
  • different data filtering options (migrate only what you need);
  • more control over IMAP migrations;
  • intuitive user interface (no PowerShell skills required);
  • competitive price.

See a full comparison of CodeTwo Exchange Migration vs Exchange native migration tools.

Can I test CodeTwo Exchange Migration before buying it?

Yes, you can.

Unless activated with a paid license key, CodeTwo Exchange Migration is functional for 30 days, with the only limitation being that you can migrate a maximum of 10 items per folder. This means that if you’re using the program to migrate e.g. a user’s mailbox, only 10 emails from each mail folder, 10 calendar items from each calendar, 10 contacts from every contacts folder, etc., will be migrated.

Once you purchase the license and activate your copy of CodeTwo Exchange Migration, you can resume the migration and move all remaining items.

You can download the CodeTwo Exchange Migration installer here.

How does CodeTwo Exchange Migration work?

The program performs Exchange-to-Exchange migrations by accessing your source server mailboxes via Exchange Web Services (EWS) or MAPI (used primarily for legacy versions of Exchange Server) in order to read their contents. Then, the selected data is copied to the target server mailboxes (this time only via EWS).

To connect to an on-premises Exchange server, the user operating the program needs to have certain management roles assigned. If any required role is missing, the program will help you assign them. To establish a connection with source Office 365 (Microsoft 365) tenant, CodeTwo Exchange Migration is registered in that tenant’s Azure Active Directory. The registration can be performed automatically by the program (which is perfectly safe, as the program authenticates with your Office 365 tenant using OAuth 2.0 tokens), or you can decide to register the program by yourself (learn more).

During IMAP migrations, CodeTwo Exchange Migration reads data from email folders in source email accounts using the IMAP protocol, and then copies these folders and their contents to mailboxes on the target Exchange server.

It is necessary to have mailboxes prepared in the target environment prior to migration. If they are missing, you can automatically create them directly in the program. CodeTwo Exchange Migration can also automatically match source mailboxes with their target counterparts.

For more details on how the program works, see this article.

Can I migrate from Office 365/Microsoft 365?

Yes, you can. CodeTwo Exchange Migration lets you migrate mailboxes and public folders from Office 365 (Microsoft 365) to Exchange 2019, 2016, 2013 or 2010.

Learn more about migrating from Office 365 in the user’s manual.

Are migrations from Google Workspace, Zimbra and other non-Exchange platforms supported?

Yes, CodeTwo Exchange Migration supports migrations of emails from those and other servers, e.g. HCL Notes (formerly IBM Notes and Lotus Notes), Google Workspace (formerly G Suite), Zarafa or Kerio Connect via the IMAP protocol. Compared to IMAP migration tools provided by Microsoft, CodeTwo Exchange Migration gives you control over many more aspects of the process. For further details, see this page.

When migrating from IMAP servers, there are two limitations that you should be aware of:

  • you can only migrate email folders (due to the IMAP protocol limitations),
  • you have to provide credentials for all user accounts that you want to migrate.

Are migrations from hosted Exchange environments supported?

Yes, they are. 

To migrate from hosted (e.g. Rackspace) or other limited-access Exchange Server, the program uses the IMAP protocol to connect to the source server. Before the migration, make sure that IMAP4 is enabled on the source server, so that CodeTwo Exchange Migration can access source email folders and then replicate their contents in target mailboxes.

For further details see this page.

Will the program migrate encrypted emails?

The program will migrate encrypted emails as regular emails, which will be then normally accessible on the target server. The email encryption configuration will not be migrated and it needs to be reconfigured after migration. All emails from the source server are copied “as such” to the destination server and look exactly as the original.

Can the program migrate items between servers with different language versions?

Yes. CodeTwo Exchange Migration supports all languages, regardless of the language on the source and the target server. The software moves all special language characters so that all items can be migrated with no issues. Learn more in the user’s manual.

Do I have to pay to get support?

No, technical support for this product is included in the license price. Our team can be reached via phone or email. When necessary, online sessions are performed to help resolve issues. You can find out more about our technical support program on this page.

Additionally, we have made technical documentation for CodeTwo Exchange Migration available online for all users:

How is CodeTwo Exchange Migration licensed?

The application is licensed based on the number of source mailboxes you want to migrate. Each mailbox consumes 1 license once you start a migration job. To migrate public folders, you need to use up 25 licenses (this number is fixed; it does not matter how much data is contained in these folders).

For example, you purchased a 50-mailbox license and used our product to completely migrate 25 mailboxes and started migrating 10 more mailboxes. In this situation, you would have 15 seats left and could use them to migrate another 15 mailboxes from the source server.

Our licensing model also lets you use the remaining seats for a different migration project, e.g. migrate another source server.

For more on licensing, consult this article.

Can I purchase additional licenses after my initial purchase?

Yes. You can do this by selecting the Additional licenses option in the first step of the online order form.

If you need to purchase additional licenses for your current 2.x or 1.x version of the program, we recommend purchasing a 3.x license key for as many additional mailboxes as you need. Upgrade your program to version 3.x (the upgrade is free of charge for version 2.x and version 1.x users) and migrate the remaining mailboxes.

Find out how to perform an upgrade

What type of data can be migrated using CodeTwo Exchange Migration?

To learn more on what type of data is supported for migration, see this section of the user's manual.

Where do I install the program?

You can install CodeTwo Exchange Migration anywhere in your source server domain – even on a workstation. If you are migrating from Office 365 (Microsoft 365), install the program on your target Exchange server.

How long does the migration process take? Are there any size or speed limits?

An average migration speed is between 500 MB and 2 GB per hour. However, the duration of the entire migration process depends on various factors.

CodeTwo Exchange Migration does not impose any limits on the size of migrated mailboxes and mailbox items nor on the migration speed. However, it might be possible that your Exchange Server imposes its own limits, which our program will not be able to override.

You also need to consider other environment-specific factors that can limit or increase the migration speed, including the quality of your internet connection (in the case of a migration to a different network), your local router throttling, source and target server throttling, performance of the computers involved, etc. Learn more...

Refer to the articles linked below to find out how to check and modify the native Exchange Server migration size and speed limits:

How is a direct migration from Exchange 2010 to 2019 possible?

Exchange Server 2019 does not support coexistence with Exchange Server 2010 (as well as with 2007 and 2003). This is Microsoft’s limitation (see this article for more). Therefore, only cross-forest migrations from Exchange 2003 to Exchange 2019 are possible.

Using only the tools provided by Microsoft, to go from Exchange 2010 to Exchange 2019, you would have to perform a double hop migration (i.e. update Exchange to 2013 or 2016, and then migrate to Exchange 2019). With CodeTwo Exchange Migration, this is not necessary, as the program can move mailboxes directly between any two Exchange Server editions. See this page to find out more.

Learn more about migrating from Exchange 2010 to Exchange 2019

How do I prepare my environment for the migration?

The requirements vary depending on the server which will be acting as the source in your migration. In this user’s manual article you will find links to information about preparing for all available migration scenarios.

Does the program support multi-factor authentication when migrating from Office 365/Microsoft 365?

Yes, it does. You can use your MFA enabled admin account when setting up a connection to the source Office 365 (Microsoft 365) server.

Can CodeTwo Exchange Migration auto-match source and target mailboxes?

Yes. CodeTwo Exchange Migration can match source and target mailboxes based on various predefined and custom attribute patterns. The default pattern will connect mailboxes based on users' names and display names. The program also allows you to match mailboxes manually. Learn more...

How does the program create mailboxes on the target server?

If during the auto-matching process the program detects that any of the source mailboxes do not have their counterparts on the target server, it will propose creating these mailboxes based on a set of source mailbox data. You can modify this set using a range of mailbox properties. Learn more...

Does CodeTwo Exchange Migration migrate public folders? How does this work?

Yes, CodeTwo Exchange Migration does migrate Exchange public folders. You just have to enable public folders on the target server (in the case of Exchange Server 2013/2016/2019, create a mailbox for them) and configure the program to include public folders in the migration. Our software will recreate the source server public folders tree on your target server and copy all items. In addition, the admin account used in the program to connect to the target Exchange server needs to be granted the Owner rights to all folders to which the data will be migrated (including the root public folder).

Additionally, bear in mind that migrating public folders reduces your CodeTwo Exchange Migration license by 25 users.

Can I migrate public folders in the same Active Directory forest?

No, you cannot. Exchange Server does not let you create the second public folder infrastructure in the same AD forest. Because of that, CodeTwo Exchange Migration lets you migrate public folders in a cross-forest migration scenario only.

It is also not possible to migrate public folders in a hybrid environment because you cannot have public folders in both on-premises Exchange and Office 365 (Microsoft 365) at the same time.

Does the program migrate free/busy statuses?

Free/busy statuses are generated ad hoc by the Exchange Server Availability Service, based on the content of users' calendars.

CodeTwo Exchange Migration migrates users' mailboxes, including their calendars. This means that, provided you have created users' accounts in AD and did not limit free/busy permissions in any way, the Availability Service will automatically update the free/busy statuses.

Does the program delete anything from the source server?

No, it doesn't. CodeTwo Exchange Migration accesses the source server data passively, which means that no data is deleted or modified on your source server.

Can source mailboxes still be used after they have been migrated?

Yes, they can. The data on the source server is not modified in any way, so you can keep using the source mailboxes without any limitations. If you do so, and later on want to migrate the new items that have been created in the process, simply click the Rescan button and the program will update the mailboxes on the target server by copying these items.

Help! Target server mailboxes addresses are not resolving and are not listed!

In some migration scenarios, such as a cross-domain migration, the target server email addresses may not resolve or be listed. In these cases, target mailboxes have to be selected manually by providing their addresses.

Is it possible to migrate mailboxes within the same domain using your program?

Yes, provided that the User Principal Names (UPN) of the source and target mailboxes are not the same. 

For example, it is not possible to migrate from server A to server B within the same domain, e.g., if both the source and target mailboxes are named In order to successfully carry out such a migration, you have to create a different mailbox for this user in the target location and name it differently, e.g.

Please note that other limitations still apply. Coexistence of Exchange 2003 and 2013/2016/2019, 2007 and 2016/2019 or 2010 and 2019 is not possible. Therefore, in this case a direct migration is only possible in a cross-forest scenario, which is fully supported by CodeTwo Exchange Migration. 

I am getting an error...

If you have encountered any problems with the application, follow the steps from Knowledge Base article about troubleshooting CodeTwo Exchange Migration.

If none of the suggestions from the article help, contact our Technical Support team.

We have also made all technical documentation for CodeTwo Exchange Migration available online for users. Use the below links to get to:

How to upgrade to version 3.0?

In order to upgrade CodeTwo Exchange Migration to version 3.0, you need to follow the steps from this article.

Update to CodeTwo migration tools – support for OAuth 2.0 and performance improvements

A new version of CodeTwo Office 365 Migration and CodeTwo Exchange Migration is out. With this release, we’ve added another layer of security to our migration tools by switching to the OAuth 2.0 authorization protocol to access Office 365. We’ve also completely redesigned Office 365 connection wizards and introduced modern APIs that further improve the performance [...]

CodeTwo migration tools upgraded – new licensing model and support for Office 365 Germany

We are happy to let you know that our migration tools, CodeTwo Exchange Migration and CodeTwo Office 365 Migration, have been upgraded to version 3.0. Along with this upgrade, we have implemented significant enhancements and changes which include a completely new licensing model and support for Office 365 Germany. What’s new in version 3.0? This [...]

Faster migration and RBAC – new update to CodeTwo migration tools

We have released a new update to our migration tools CodeTwo Exchange Migration and CodeTwo Office 365 Migration. The newest version brings two significant improvements – the Role Based Access Control model (RBAC) to manage access permissions and even faster and more stable migration. Minimum permissions to manage the program Thanks to implementing the RBAC [...]

Migration from Office 365 and Exchange 2016 – new features in CodeTwo migration tools

With the newest update, CodeTwo Exchange Migration and CodeTwo Office 365 Migration have just received new features. The new version introduces some major changes and unlocks new migration scenarios: Gives the option to migrate from Office 365 to Exchange Server Supports mailbox migration between Office 365 tenants Allows to set size limit for migrated items [...]

How to migrate Exchange public folders to Office 365 using CodeTwo Office 365 Migration?

If you need to migrate public folders from an on-premises Exchange Server to Exchange Online (Office 365), you have two options to choose from: migrate public folders using a native solution or use a third party application like CodeTwo Office 365 Migration. CodeTwo Office 365 Migration minimizes the resources you need to use to perform [...]

Automatically create mailboxes when migrating to Exchange or Office 365

We've just released new versions of CodeTwo Exchange Migration and CodeTwo Office 365 Migration. The two major improvements included in the release are: the target mailbox/account creation capability and the new options available in the Automatch feature. CodeTwo Exchange Migration and CodeTwo Office 365 Migration now allow for conducting migrations even if users' target accounts [...]

IMAP migration from Google Workspace, IBM/Lotus Notes, Zimbra to Exchange or Office 365

If you are preparing a move from Google Workspace (formerly G Suite), IBM/Lotus Notes or Zimbra (or any other server that supports IMAP) to Microsoft Exchange or Office 365, you may want to take a look at CodeTwo migration solutions. The two applications have just received an update which, aside from several minor fixes and [...]

CodeTwo Exchange Migration and CodeTwo Office 365 Migration – introducing Jobs and new UI – Versions 2.0 out now!

With the newest versions 2.0 of CodeTwo migration software we have much more to expect as both products have undergone major improvements. Now we can experience better management of performed migrations which are now displayed as Jobs and it is all set in a new UI. CodeTwo Exchange Migration and CodeTwo Office 365 Migration will prove more [...]

Migrate legacy (2003 or 2007) Exchange to Exchange 2016

Update: this post was updated on October 24, 2017. Microsoft has stirred up a quite load of enthusiasm by the recent appearance of Exchange 2016. As the new version raised inquiries among IT professionals for new solutions, Microsoft in fact did not soothe this yearning for any cutting-edge technologies. You get a bundle of improvements, [...]

Update to migration tools: new reporting features added

It's been exactly two years since the first release of CodeTwo Exchange Migration and CodeTwo Office 365 Migration, our twin solutions for Exchange-to-Exchange and  Exchange-to-Office 365 migrations. Those two products have come a long way since they premiere, gaining: better performance, improved stability and new important features. Today marks the next milestone in the development process. [...]

Office 365 and Exchange migrations: +10 to stability

Following 3 weeks of intense coding and debugging, we're happy to announce the release of twin 1.9 versions of our CodeTwo Exchange Migration and CodeTwo Office 365 Migration solutions! The update includes several improvements, the most important of which is the replacement of a module that, in specific scenarios, had been causing software crashes. The [...]

New time filters in CodeTwo Exchange/Office 365 migration tools

Last week we released an update to CodeTwo Exchange Migration and CodeTwo Office 365 Migration, our mailbox migration tools for Exchange Server and Office 365. Apart from fixing some minor bugs, we have also added new important features. One of the most important changes applied in this release is the possibility to filter out mailbox [...]

CodeTwo Exchange Migration 1.7.1 and CodeTwo Office 365 Migration 1.7.1 is available

Recently we have published new versions (1.7.1) of CodeTwo Exchange Migration and CodeTwo Office 365 Migration which are now available for download. Amongst new features you can find: Folder type selection. You can choose what specific item types are migrated – emails, tasks, contacts etc. Migration priority. Decide which mailboxes should be copied first and [...]

CodeTwo is Microsoft Gold Partner

CodeTwo just renewed and continues to hold its Gold partnership with Microsoft for another year in the row – hooah! This means that our software is of the highest grade, and was thoroughly tested and reviewed by users. Earlier this year we received the Cloud Accelerate badge! We earned it due to the growing base [...]

CodeTwo Exchange Migration 1.6.0 and CodeTwo Office 365 Migration 1.6.0 released!

Today we have published new versions of our migration software – CodeTwo Exchange Migration and CodeTwo Office 365 Migration. Both programs are now available for download in version 1.6.0. This release contains a number of small programmatic fixes, new reporting features and migration statistics visible in the GUI, and more importantly the migration speed improvements. [...]

Exchange 2013 migration guide and checklist – free PDF download

We know exactly how difficult it can be to perform complete migration in an Exchange-to-Exchange scenario. Things get even more complicated when the source and destination servers are located in separate forests, or when it comes to migrating from Exchange 2003 directly to Exchange 2013.  Having all these difficulties in mind, we developed and launched [...]

Migrate to Exchange Server and Office 365 in time frames – new Scheduler feature is here!

As the New Year is knocking at the door, we don't put our feet up and prepare for the celebration but continue to work on improvements in our Exchange Server and Office 365 migration tools. As promised in our recent blog post, we have just implemented new features in CodeTwo Exchange Migration and CodeTwo Office 365 [...]

CodeTwo migration tools reviewed by Microsoft Exchange MVPs

It has been almost half a year now since the release of our migration tools for Exchange Server and Office 365. During the last few months we have gathered a lot of feedback about what can be done better and what new features to implement. Thanks to the hard work of our programmers CodeTwo Exchange [...]

End of support for Exchange 2003 – where to migrate in 2014?

Microsoft will be soon withdrawing support for Exchange 2003 and some other related products, like Outlook 2003, or Windows XP. The extended support phase for these platforms ends April 8, 2014. If you still use Exchange 2003 as a base of your email system it is right about time you thought about upgrading to Exchange [...]

Migrations to Exchange Server and Office 365 – new updates released

Are you planning to switch to Exchange 2013, or Office 365 anytime soon? Or maybe you need to migrate your mailboxes to another Exchange Server forest, and need a reliable tool that would reduce the time, cost and resources consumption? If your answer is “yes” to any of those questions, we've got some good news [...]

Manage inbox rules in Office 365 and Outlook on the web

Inbox rules in Office 365 (or Microsoft 365, if you like the newer name better) help users and admins make Outlook a better place. They can be employed to fight distractions, get things organized, block unwanted correspondence or automatically forward selected emails. With the never-ending onslaught of information that flows into Outlook, they are invaluable. [...]

How to create a no-reply mailbox in Microsoft 365

No-reply email addresses are useful in many scenarios, like sending notifications from transaction systems, shipping progress information, etc. In the case of such messages, you do not expect any user feedback and most of them are generated and sent automatically. Even though you cannot stop users from sending emails to a no-reply address, you can [...]

Mailbox size in Microsoft 365 (Office 365)

Microsoft 365 (or to be more precise, Exchange Online) has certain mailbox size limits. Those limits depend on two variables: the subscription plan assigned to the mailbox and the mailbox type. This article shows what the maximum mailbox size is, how to increase mailbox size, how to check the current mailbox usage for all mailboxes [...]

What to do if you cannot create an app password in Microsoft 365

Some applications and services for Microsoft 365 (for example, Skype for Business) use app passwords as an authentication method when multi-factor authentication (MFA) is enabled. The problem is that after enabling MFA for the organization, some or even all users may not be able to create and use app passwords. This article shows what you [...]

How to send an HTML message in reply to a plain text email

If you have ever received a plain text email, you will know the message format will remain the same when you reply to it or forward it. Because of that, you won't be able to add hyperlinks, formatting and images to your email. What's more, instead of your carefully designed HTML email signature, the recipient [...]

How to create and manage Microsoft 365 security groups

Microsoft 365 security groups, formerly known as Office 365 security groups, allow admins to easily manage access to e.g. SharePoint sites by grouping together users that require identical permissions. This way you only need to assign access once for the entire group, not for each user individually. In this article, we will show you how [...]

How to set up out of office replies in Office 365

Out of office messages in Office 365 (let’s assume Office 365 = Microsoft 365, to make things easier) are an extremely useful thing. Not everyone knows though that this simple automatic reply is more than just an email. In this article, I’ll quickly go over the basics: what out of office message in Office 365 [...]

End of Mainstream Support for Exchange 2016

End of Mainstream Support for Exchange 2016 is planned for October 13, 2020. It means that 5 years after its release, this on-premises server enters the Extended Support period. The end of extended support (or end of life) for Exchange Server 2016 is planned for October 14, 2025. Read on to learn how this affects [...]

Blocking basic authentication in Office 365 (Microsoft 365)

The article was updated on February 25, 2021 Due to the Covid-19 pandemic, there was a huge change of plans concerning disabling basic authentication in Microsoft 365 (for connections to Exchange Online). The complete shutdown has been postponed indefinitely. While it gives organizations much more time to prepare, it’s a good idea to get tenants [...]

VBScript: create an HTML Outlook email signature for the whole company

In one of my previous articles, I’ve shown how to create simple email signatures in Outlook using VBScript. In this article, I will show you how to take your email signatures to a higher level. I will use VBScript to create an HTML email signature for every Outlook (for Windows) installation in your organization. The [...]

Manage student profile pictures in Microsoft 365, Teams, Outlook and more

As the digital transformation increasingly affects education, IT administrators in schools all over the world have their hands busier than ever. With limited time available to get everything ready for online classes and modern communication between teachers, students and parents, every second matters. One of the challenges IT administrators have to face when working with [...]

How to block access to your Exchange Online organization using Client Access Rules

Client Access Rules in Exchange Online are rules that you can use to control which client connections are allowed and not allowed to access your Exchange Online organization. They let you define the conditions based on various properties of a client. These can be, for example, the protocol they use to connect, their IP address [...]

How to recover user emails in Microsoft 365

If you are a Microsoft 365 administrator, it’s only a matter of time before you are tasked with restoring deleted emails (or other mailbox items). While you can use eDiscovery to recover deleted items, there is an easier way which lets you restore deleted items straight back to where they originated from. Below, I’ll describe [...]

How to prevent users from changing profile photos in Microsoft 365

Update: This post was updated on July 22, 2020. When you set up user photos in Microsoft 365 (Office 365), they propagate through the whole Microsoft 365 tenant and apps integrated with Azure AD. This means that they are displayed in Outlook, Teams, SharePoint, and more. By default, any user can change their photo to [...]

SBS 2011 to Microsoft 365 migration

SBS (Small Business Server) 2011 is basically Windows Server 2008 R2 packed together with Exchange 2010 into a single suite. As such, you would expect migrating SBS 2011 to Microsoft 365 (Office 365) to be similar to migrating Exchange 2010 to Office 365. As it turns out, there are some differences that impact the migration [...]

Export Microsoft 365 mailboxes to PST with PowerShell

Exporting Microsoft 365 mailbox content to PST is usually used for litigation purposes. However, it also works as a workaround for backup, archiving and migration. In a previous article, I’ve shown you how to use this mechanism with the eDiscovery tool. This article demonstrates how to produce similar results using PowerShell and New-ComplianceSearch cmdlet (with [...]

How to quickly check installed software versions

There are situations where you need to check whether you or your users have certain software installed, and what is its version. You may want to check if the software is up to date or if your GPO-deployed software has been installed for a certain user. I’ll show you several methods you can use to [...]

How to add user photos to Office 365 without PowerShell

When users can see each other’s photos, online conversations and collaboration become more personal. In large organizations, the reason for using photos may be even more pragmatic. It may be the only way for people to actually see who they are talking with. This is why companies want to display users’ photographs in Office 365 [...]

New-ComplianceSearch: how to use the newer version of Search-Mailbox

[Update]: This blog post was updated on April 3, 2020. As announced in this Microsoft article, the date for retirement of legacy eDiscovery tools is moved from April 1, 2020 to July 1, 2020. That is when Search-Mailbox cmdlet will no longer be available. This means that all scripts using Search-Mailbox need to be rewritten [...]

How to back up Exchange Online mailboxes

The question should no longer be whether to back up Exchange Online mailboxes or not, but how to do it. It’s no secret that your Office 365 data isn’t a responsibility of neither Microsoft nor any Office 365 services provider. To make sure your Exchange Online mailbox data is available and recoverable at all times, you [...]