On 07/28/2016 10:54 AM, sgironella@schema31.it wrote:
Enabled IMAP and SMTP debug (see attachments) and tested against a DBMail internal mail server and an external one (GMail to simplify test repeatability).
Attached files are related to the GMail session.
As you can see, IMAP response differs on main mime part headers structure, so i think that's the reason for sign verification failure.
I created a ticket for this issue https://github.com/roundcube/roundcubemail/issues/5371
I don't see a simple workaround now, we'd need to get the whole signed message body and parse it instead of fetching headers and body of the first part separately. I'll take a look at this over the weekend.