AIP + SMIME + external users = unreadable email?

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Hi guys,


Can you verify that emails signed with a SSL certificate (SMIME) + AIP "Do not forward" (sent from the latest Outlook 365 ProPlus 2016 on Windows 10) work properly with external email accounts (for example



IMHO it is not working properly:

I get the "old" message "This message is protected with Microsoft Information Protection. You can open it using Microsoft Outlook, which is available for iOS, Android, Windows, and Mac OS. Get Outlook for your device bla bla bla" and message.rpmsg




When I use just AIP "Do not forward" (without SMIME signing), the resulting email is readable:


What am I doing wrong? And how can fix it?

4 Replies

Hi @Deleted, did you happen to figure his out?  I am having the same issue.



@slm2112nope, so far I have no solution, and recently my SMIME certificate expired. I will retry some time later ;)

@Deleted did you ever resolve this? we're having similar issues but can't find anything on the web on this.

No, I gave up.