CodeTwo Email Signatures for Office 365 is a cloud-based software for Office 365 tenants, designed to add email signatures and disclaimers to outgoing and internal Office 365 emails. The signature/disclaimer adding mechanism is based on rules. The software lets every Office 365 administrator create rules to centrally manage email signatures via an easy-to-use administration panel which is launched directly from a CodeTwo website. The main software engine - the CodeTwo Email Azure Service - processes emails on Microsoft Azure servers and stamps signatures on the fly. This makes the software installation-free for both administrators and users. All email clients and mobile devices are supported.

Architecture of CodeTwo Email Signatures for Office 365.
Fig. 1. The program adds signatures to emails sent from from any device.

How it works

The software is a cloud-based service that resides in Microsoft datacenters on Microsoft Azure servers. During the initial configuration, the program creates connectors in your Exchange Online organization to reroute all outgoing and internal emails from your Office 365 tenant through the CodeTwo Email Azure Service for processing. When a user sends an email from an Office 365 account (regardless of the email client) as shown in Fig. 2. point 1., it is forwarded to the CodeTwo Email Azure Service which checks emails against conditions the administrator configured (Fig. 2. point 2.) and stamps them with signatures if these conditions are met. In any case, the email is then sent back to the original Office 365 tenant (Fig. 2. point 3.) which delivers it to the final recipient in a usual way (Fig. 2. point 4.).

Architecture of CodeTwo Email Signatures for Office 365.
Fig. 2. Architecture of CodeTwo Email Signatures for Office 365.

Security and performance

Even though CodeTwo Email Signatures for Office 365 reroutes your email via a third-party Microsoft Azure service, it is absolutely secure for your business.

The program:

  • does not accept emails from random mail servers. Only emails received from Office 365 tenants registered with CodeTwo are processed;
  • does not move emails to any third-party servers for processing. The CodeTwo Email Azure Service is installed on Microsoft Azure servers which host Office 365 tenants, so your emails never leave Microsoft's servers;
  • does not store, copy or forward your emails anywhere. Received emails are released back to the original server and deleted from CodeTwo servers after the processing;
  • does not log any email content or properties other than Message-IDs and time stamps (required for proper monitoring and troubleshooting of the software behavior);
  • does not modify any email content or properties except for:
    • inserting signatures into their body,
    • adding appropriate Internet email headers (the number of hops registered in headers will rise from x to 2x+1 where x is your usual number of hops, e.g. if normally it is 3, then after deploying CodeTwo Email Signatures for Office 365 it will increase to 7 - this is required by common Internet email exchanging protocols and does not affect the end users at all),
    • adding three header properties (Received, X-CodeTwoProcessed, X-CodeTwo-MessageID) to identify the already processed emails and avoid double stamping of signatures and loop processing;
  • does not modify email senders or recipients. An email processed by CodeTwo Email Signatures for Office 365 looks for recipients (and their email clients and servers) in exactly the same way as emails sent directly from Office 365. No shady-looking domain swaps or sending as / on behalf. Thanks to the Azure OAuth 2.0 authentication the program does not store any clients’ credentials;
  • does not delay email delivery by more than a few seconds. In our tests, with average Office 365 standalone email delivery times of around 40 seconds, CodeTwo processing took only around 8 additional seconds;
  • is bottleneck-resistant. As our CodeTwo services are installed in the Microsoft Azure cloud, their processing power is fully scalable.


As CodeTwo Email Signatures for Office 365 runs entirely in the cloud, there are no requirements when it comes to the admin's or users' computers. No permanent components are installed on any client-side on-premises server or workstations. 

We only expect that you have a supported Exchange Online / Office 365 plan and Global Admin credentials for your organization's tenant, and one of the modern web browsers running on Windows (Internet Explorer 9 or higher is recommended).

Before installing, please read about the supported platforms and requirements.

Software installation and initial configuration

Setting the software up is as easy as going through configuration wizards that will automatically register your Office 365 tenant to the program and configure your Exchange online connectors. The only thing left to do is launch the Admin Console to manage your signature rules. To read about the program's components, click here. You can also find out more on the installation and configuration process in this article.

Installation administration and signature rules management

Since the software is installed in the cloud and no local components have to be in place, managing the software installation is basically limited to making sure you have it licensed. All the time you normally waste on maintaining, updating or troubleshooting your on-premises installations is saved and you can enjoy using the software's built-in WYSIWYG editor to compose your perfect signature. This Installation process article also covers basics of using the editor.


The software is completely transparent for end users. As the CodeTwo Email Azure Service works in the cloud, the process of stamping signatures to emails is invisible and independent of the end-users' email clients or actions. Once configured and started, CodeTwo Email Signatures for Office 365 will add signatures to every email sent from Office 365 accounts that meet the conditions defined in your rules. Signatures are added regardless of the email client used - it works with OWA in Office 365, Outlook and other popular email clients - both desktop and mobile versions.

See next

Frequently Asked Questions

Understanding the program

Was this information useful?