Bug 409456

Summary:	KMail can not deal with PGP messages sent by Exchange
Product:	[Applications] kmail2	Reporter:	Fabian Vogt <fabian>
Component:	general	Assignee:	kdepim bugs <pim-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	ellenpapsch
Priority:	NOR
Version First Reported In:	5.11.2
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Fabian Vogt 2019-07-03 12:50:33 UTC

Exchange (in this case Office 356) mangles PGP encrypted messages when sending.

Content-Type: multipart/encrypted; boundary="nextPart6734939.BlDrd8uHN9"; protocol="application/pgp-encrypted"

ends up as

Content-Type: multipart/mixed;
	boundary="_003_2390612FqyDRV8H2nlinuxe202susede_"

And so KMail is unable to show the mail correctly. By editing the content-type to say multipart/encrypted, it's displayed correctly.

See also https://gitlab.com/enigmail/enigmail/blob/master/package/fixExchangeMsg.jsm#L224 how enigmail deals with this.

Comment 1 Ellen Papsch 2021-01-09 18:21:06 UTC

Some more information:

Messages are not garbled if only signed.

GNOME Evolution also had the discussion regarding a workaround some time ago: http://gnome-evolution-general.1774414.n4.nabble.com/Evolution-3-18-5-2-Encryption-with-GPG-from-Hotmail-Account-message-structure-td4665706.html

I also got Office 365 SMTP working. Their SMTP server does not have the problem.