When sending an S/MIME mail with GpgOL according to the forum Exchange 2016 returns an error ( https://wald.intevation.org/forum/message.php?msg_id=5745&group_id=11 )
I myself can reproduce this with an Outlook.com account.
Generating server: VE1EUR02HT158.mail.protection.outlook.com
aheinecke@intevation.de
Remote Server returned '550 5.6.0 M2MCVT.StorageError.Exception: ConversionFailedException, Content conversion: Invalid S/MIME encrypted message.; storage error in content conversion.'
| rO GpgOL | |||
| rOf79f3379aba5 Fix S/MIME encryption with latest Exchange 2016 | |||
| Status | Assigned | Task | ||
|---|---|---|---|---|
| Resolved | • aheinecke | T3742 Gpg4win 3.1.0 | ||
| Resolved | • aheinecke | T3864 Gpg4win-3.1.0 Release blocker | ||
| Resolved | • aheinecke | T3853 GpgOL: S/MIME + Exchange 2016 Can lead to 550 5.6.0 M2MCVT.StorageError.Exeption |
Playing around with this a bit: I can get messages to pass if I set the content type of our MOSS attachment to multipart/encrypted .
The problematic thing there is that there is a comment in the code that explicitly states that multipart/signed is needed to activate MSOXSMIME. So we have to be careful, maybe even check the Server Version somehow as I don't want to break older stuff.