Troubleshooting
Current versions of Signature 365 software
See the current released versions of Signature 365 add-ins, agents, and connectors, plus how each update method works.
Supported Outlook versions for Signature 365 client signatures
Compare supported Outlook versions and features for the Signature 365 modern add-in and Classic Agent.
Nested app authentication (NAA) and deprecation of Exchange legacy tokens
Learn how Exchange legacy token deprecation affects Signature 365 and choose between upgrading to NAA, granting permissions, or re-enabling tokens.
Outlook add-in is not being deployed to users as expected
Troubleshoot delayed or missing Signature 365 Outlook add-in deployment in Microsoft 365, including wait times and direct group membership.
Outlook add-in is not adding default signatures to email
Fix Outlook on Windows not auto-inserting Signature 365 default signatures by updating to the required Outlook build.
How to enable remote logging in the Outlook add-in
Enable remote logging in the Signature 365 Outlook add-in so support can diagnose issues across supported Outlook clients.
Outlook add-in: Opening the Outlook devtools debug window
Open the Outlook devtools window in New Outlook, classic Outlook, or OWA to capture Signature 365 add-in console logs.
Creating a security group using dynamic group membership
Create an Entra ID dynamic security group to deploy the Signature 365 add-in automatically while excluding selected users.
Disabling Outlook signatures in New Outlook and OWA
Disable built-in signatures in New Outlook and Outlook on the web using Exchange admin center OWA policies.
Existing outlook email templates insert signature above email body
Fix signatures appearing above existing Outlook template content by recreating the email template.
HTML tags are shown for weblinks and images
Resolve Outlook showing hyperlink or image field codes by toggling the built-in Document Properties view with Alt+F9.
Outlook Classic inserts a ? instead of the correct character when adding a Signature 365 signature
Fix Outlook Classic replacing accented or special characters with question marks when inserting Signature 365 signatures.
Outlook Desktop - Images appear as attachments when email is saved as draft
Understand the Outlook desktop draft bug that shows embedded signature images as attachments and Microsoft's pending fix.
Signature 365 agent authentication script error
Fix Signature 365 agent authentication script errors by switching authentication to the system browser with the required registry setting.
Signature 365 Classic Agent cannot support Microsoft One Outlook
Learn why the Signature 365 Classic Agent cannot work with Microsoft's new Outlook and how to block the switch.
Signature 365 Outlook add-in is removed after log out
Prevent the Signature 365 Outlook add-in disappearing after log out by preserving Outlook cache folders on roaming-profile environments.
Signature images appear as attachments in web mail services
Understand why Gmail and other webmail services show embedded signature images as attachments, and when to consider hotlinked images.
Using S/MIME with Outlook mobile
Configure Outlook Mobile S/MIME by importing trusted certificate authorities into Exchange Online and uploading an SST file.
Using the Aptos font in Signature 365
Use Aptos in Signature 365 by installing the font on sending and receiving devices, despite browser and OWA limitations.
Using the Outlook mobile add-in in GCC environments
Enable the Outlook mobile add-in in Microsoft 365 GCC environments by changing the required Exchange Online PowerShell setting.
Version requirements for the Outlook mobile add-in
Check the Outlook Mobile and Signature 365 add-in versions required to use client-side signatures on iOS and Android.
Creating a security group using dynamic group membership
Create an Entra ID dynamic security group to deploy the Signature 365 add-in automatically while excluding selected users.