> >> The choice of 521 here seems rather unfortunate, and based on an > >> error the experimental RFC 1846. Please consider 550 or similar. > > > >That's part of the problem: None of the existing codes that can be returned in > >response to RCPT TO are right for the job. 550 is a mailbox access error, 552 > >is a storage allocation error, 553 is an invalid mailbox error, and 555 is a > >parameter problem. Out of all these 553 is probably the closest, but it is > >still not quite right. > I share your opinion that anything that breaks is already broken, but > considering how widely used Postfix is, it might well be better > engineering to switch to a 553 code. Topic already raised in > appsarea. That's a fair point. I dislike having to make such accomodations, but the reality on the ground is what it is, and needs to be considered. Ned