Since I've upgraded to dovecot 2.0.13 + Pigeonhole 0.2.3 (Gentoo package) I've received a few complains of users about rejected messages.
Investigating the problem, I've seen that when the external sender server publishes SPF information, when some message is sent from there to one of my users that has a Sieve redirect action active to another external system (that does SPF validation), the message is rejected because our system only changes the envelope "rcpt to" in the redirection and the "mail from" remains the original. When the end server does the SPF validation it fails because my server isn't in the IP allow list for the domain of the original sender.
I never seen this problem in the old Dovecot+CMUSieve.
Shouldn't the sender be changed in the envelope "mail from" from the original one to the recipient that made the Sieve redirection?
Keep the excellent work with dovecot and related projects!
TIA!
-- Best regards,