Relevant Products: Exclaimer Cloud - Signatures for Office 365
You are using the Cloud Signature Update Agent and some of your users are receiving the following prompt and some are not:
This is due to some users having multiple mail accounts in their Outlook profile.
The signature update for users with multiple mail profiles is completed within the registry and as a result of this, Outlook does indeed have to be restarted in order for the changes to go through.
Users who only have a single mail account within their Outlook profile have their signature information updated directly into the the Outlook mail settings and are therefore not required to restart Outlook.