CodeTwo Outlook Add-ins overview

CodeTwo Email Signatures for Office 365 lets you set up client-side signatures (Outlook signatures) that are automatically added to emails in Outlook as users type. You can set up default signatures for new messages and for replies/forwards. Users can also manually select a different signature in Outlook.

Client-side signatures are added by an Outlook add-in that can be deployed organization-wide. There are two CodeTwo add-ins that you can use: 

  • New experience: CodeTwo Signatures Web Add-in for Outlook that works with Outlook for Windows, Outlook for Mac (early access) and Outlook on the web (OWA). This modern Web Add-in offers better experience and more capabilities. It can also be used to preview server-side signatures
  • Classic experience: CodeTwo Signatures Add-in for Outlook (COM Add-in) that works with Outlook for Windows only.

You can only use either of the add-ins, so deploy the one that best matches your preferences. If you have already deployed one of them, uninstall it first before deploying the other one. Otherwise, the add-ins can conflict with each other.

See the table below for a quick comparison of the two signature add-ins for Outlook available for CodeTwo Email Signatures for Office 365:

  Modern Web Add-in Classic COM Add-in
Supported platforms

Outlook for Windows
Outlook for Mac (early access)
Outlook on the web (OWA)

Outlook for Windows
Supported signature mode All Client-side & combo only
Deployment Central via the Microsoft 365 admin center

Deployment instructions
Central via GPO or Intune, or individual by Outlook users

Deployment instructions
How are signatures inserted? Automatically (event-based) or manually (via the CodeTwo Signatures pane) Automatically or manually (via the Outlook's Signatures command) 
Who gets signatures? Users defined in client-side signature rules Users defined in client-side signature rules as well as other Outlook users1
Preview of server-side (cloud) signatures Yes

Learn more
Disable users' default Outlook signatures Yes

Learn more
Yes (Outlook for Windows only)

Learn more
Switch between Outlook (client-side) and cloud (server-side) signatures Yes

Learn more
User log in requirement No Yes
How often the add-in syncs with CodeTwo services? Real-time synchronization2 Every couple of minutes or manual

1 Client-side signatures added by the COM Add-in can be accessed by and used with other accounts configured in the same Outlook app where the add-in is installed.

Changes made in the signature management app are instantly applied to signatures in Outlook.

Modern Web Add-in deployment

See the instructions below on how to centrally deploy the CodeTwo Signatures Web Add-in for Outlook to users in your organization via:


Be sure to design at least one signature template and define users who should get it. See this article to learn how to do so.

Classic COM Add-in deployment

Use the links below to learn how to deploy the classic CodeTwo Signatures Add-in for Outlook:


The COM Add-in works only with client-side signatures, so make sure that CodeTwo Email Signatures for Office 365 operates either in client-side or combo mode in your organization (learn more about signature modes). You also need to create and configure at least one client-side signature rule (see our guide on that). 

In this article

Was this information useful?