Hello,

signed PGP/MIME mails from a specific sender (using a ticket system
identifying as "X-Mailer: OTOBO Mail Service (10.1.7)") consistently
fail to verify with notmuch ("[ Bad signature (claimed key ID 0x...)
]"). However the same mail verifies fine in mutt (version 2.0.5) so I
expect it to be a bug on my side (i.e. in notmuch) rather than the
sender side.

Is anyone interested in debugging this failure? I can provide a copy of
a failing mail off-list but don't have time myself to dive into the gory
details of PGP/MIME verification right now.

Tried notmuch 0.31.4 (Debian bullseye) and 0.37 (bullseye-backports);
both fail the same way. The commits in git master since 0.37 don't look
related to PGP/MIME signature verification.

Sascha