if there is a ASN1-error while decoding the signature, no mail is displayed, just an empty window.
Even knowing that it may be technically wrong, it would be nice to ignore the error with maybe a warning and show the mail (let the user decide). Otherwise it is impossible to read that mail message at all.
Usually if there is an issue with the message body having been modified in-transit, or with a corrupt signature, the message body is still displayed but with the signature warning.
Could it be that the message became corrupt when being sent? What does it look like when opened in another email client?
I can confirm I have the same “header”, one more line about unsubscribe from a newsletter. But that does make sense, could be interpreted as a “newsletter” of some kind. But the message itself is not shown, only a blank window.
The mail is an automated message from a german parcel transport packing station. So you go there, insert your package an click “Send me a deposit receipt.”
I do not know what infrastructure that company is using and if they issue changes on that mail.
I know the use S-MIME/PGP and have documented it at http://keyserver.deutschepost.de/?language=en.
I can deliver a screenshot or source code of that mail, but only if it is not shown in public (data protection ).
I get the idea. @Domi gave a screenshot in another post, and I think it is from a similar courier service. I really can’t help with that, sorry.
That option will be displayed if they have included unsubscribe information in the message header. Something like this:
No problem, my guess is also that they are send malformed.
I will try to reach out to the operator, maybe they can fix it in their mail-template.
Thanks for your help and time.