Originally reported in the Forum: https://wald.intevation.org/forum/message.php?msg_id=6033
The problem is that the Mailing list modifies the mail and changes it from "multipart/signed" to multipart/mixed with the signed contents embedded. GpgOL does not look at "multipart/mixed" mails at all so this is currently not handled.
An example mail:
The problem is complicated because we would have to parse each multipart/mixed mail before we can know that the mime structure looks that way.
Currently we decide on a level above the actual parsing if GpgOL "touches" a Mail based on the top level MIME type.
Still an issue, just noticed that with the 3.1.12 release announcement, it really looks ugly.