The following table lists which services are and are not supported for Exclaimer:
| Category | Plans |
| Supported Email Platforms |
Exclaimer supports: Microsoft 365 Plans: Business Basic, Business Standard, Business Premium, E3, E5, F3, GCC, Office 365 A1, A3, A5, E1, E3, E5, F3 |
| Unsupported Environments |
Exclaimer does NOT support: Microsoft 365 Plans: Personal, Family, Apps, GCC High, DOD, Apps for enterprise, A1, F1, Enterprise Mobility + Security E3, Enterprise Mobility + Security E5 |
Check the system requirements for setting up and using Exclaimer, including directories, signature deployment options, client-side tools, and browsers by selecting an option below:
Exclaimer requires access to the following supported directory services to sync user information:
Microsoft 365
- Microsoft Entra ID (formerly Azure AD)
Exchange On-Premises
- Microsoft Entra ID (Works with a free Entra tenant)
Google Workspace
- Google Directory
To use server-side signatures, the following requirements must be met:
Mail Server Support (Microsoft 365)
- Microsoft 365 (Exchange Online)
Mail Server Support (Exchange On-Premises)
- Exchange 2016 CU18 and above
- Exchange 2019 CU1 and above
Mail Server Support (Google Workspace)
- Google Workspace
Mail Client Support
- All Standard mail clients supported
Client-side signatures require one of the supported Exclaimer client-side solutions listed below.
Exclaimer Signature Update Agent (Microsoft 365 and Exchange On-Premises)
The Exclaimer Signature Update Agent is supported on Windows devices that meet the following requirements:
Windows
- Microsoft .NET framework 4.6.2 (x86 and x64)
- Windows 10 or above:
- Microsoft Outlook 2016 or above
- Microsoft Outlook 2016 or above
Exclaimer Outlook Add-in (Microsoft 365)
The Exclaimer Outlook Add-in requires a supported Outlook version and Microsoft 365 mailbox:
Users whose mailboxes exist in Exchange Online
Mailbox type:
Microsoft 365 mailboxes only
Windows
- Outlook on Windows (Microsoft 365 Subscription) [version 2409 (Build 18025.20000)]
- Outlook on Windows (Retail Perpetual) [version 2501 (Build 18429.20132)]
- Outlook 2024 on Windows (Volume-licensed perpetual) [version 2408 (Build 17932.20222)]
- Microsoft Outlook Web Access
- Microsoft Windows 10, Windows Server 2016 or above
- Microsoft Edge WebView2
Mac
- Outlook on Mac [version 16.89 (24090815) or above]
NOTE: Only the New Outlook interface is supported. Go to Outlook > New Outlook to enable it.
Mobile devices
- Outlook on Android: Outlook version 4.2433.0 or above
- Outlook on iOS: Outlook version 4.2433.0 or above
Microsoft 365 Plan
Your Microsoft 365 plan must allow access to deploy Microsoft 365 Apps through Microsoft AppSource. Certain plans, such as Office 365 E2, subscriptions purchased via GoDaddy do not support this.
We recommend Using an Outlook version that supports Nested App Authentication by June 2025. The timeline below shows when legacy tokens will be disabled for all tenants.
Exclaimer Outlook Add-in (Microsoft 365)
| 17th Feb 2025 | Legacy tokens turned off for all tenants. Admins can re-enable legacy tokens via PowerShell. |
| June 2025 | Legacy tokens turned off for all tenants. Admins can no longer re-enable legacy tokens via PowerShell. Contact Microsoft for any exceptions. |
| Oct 2025 | Legacy tokens turned off for all tenants. Exceptions are no longer allowed. |
Gmail Signatures (Google Workspace)
- Gmail (web browser)
The Exclaimer portal is supported in the following web browsers.
- Google Chrome 17.x (preferred browser)
- Internet Explorer 9 or above
- Mozilla Firefox 10.x+
- Apple Safari 5 (Mac)
- Microsoft Edge
- Opera