Re: antispoofing with dovecot submission

it is possible to do antispoofing, like reject_authenticated_sender_login_mismatch from postfix ?

I could be wrong, but i believe dovecot submission is only a proxy to postfix submission. Dovecot does not directly delivery mail to the world. Meaning the mail is still passing through postfix and reject_authenticated_sender_login_mismatch would still be applied.

My follow up question would be does dovecot queue the mail or proxy it live? If postfix rejected the submission based on something like reject_authenticated_sender_login_mismatch does the email client get sent the error live by dovecot submission, or would a type of backscatter bounce be created between postfix and dovecot?