Prerequisite: You have routed your internal email traffic through our systems and have configured signatures in the Signature and Disclaimer module. (Internal Archiving)

Microsoft email products such as Outlook, Office 365, and Exchange can send email messages in a proprietary format called TNEF, which is only accepted by other Microsoft products. In the following, you will learn how to configure your Microsoft product so that it no longer sends messages in TNEF format.

• Disabling the TNEF format via PowerShell command (see below), which ensures that emails are no longer sent in TNEF format.
  Attention: This will disable the function for the entire O365 domain.

Set-RemoteDomain -Identity Domain -TNEFEnabled $false

• The deactivation can also be done via the user interface. To do so, the following steps must be taken
  • Open the 365 admin center.
  • Click on "Mail flow".
  • Then click on "Remote domains".
  • Now click on the remote domain "Default".
  • Under “Use rich-text format”, select “Never”.
  • Save the changes.

If signatures and disclaimers are still not being appended, another reason is likely responsible. Contact support with appropriate examples.