Viktor Dukhovni wrote: > > Bob Proulx wrote: > > "By default, the Postfix SMTP client moves on the next mail > > exchanger. Specify "smtp_skip_5xx_greeting = no" if Postfix should > > bounce the mail immediately. Caution: the latter behavior appears to > > contradict RFC 2821." > > > > But regardless that is exactly the answer I needed! I am going to set > > that for my friend's system as I think that is the best setting. > > Actually, it may not be. You may end up losing mail when you > encounter overloaded servers returning 554.
In my friend's case an immediate response to a message being sent just now would be better feedback. As opposed to after the bounce timeout occurs some five days later. Email is generally so very reliable these days that when we hear nothing we assume it works. And also that it went straight into the recipient's Junk folder. > In a bit of synchronicity, just a day or two ago I was corresponding > on this very question with Wietse, because there's an effort underway What a coincidence! > to polish RFC5321 with a goal of making SMTP a "full" Internet Standard > (it only takes ~40 years). As part of that, I'd like to see a couple > of the murkier bits clarified: > > * The 552 -> 452 work-around, that should no longer (if ever) > be necessary: > > > https://mailarchive.ietf.org/arch/msg/ietf-smtp/fhKAX0Z9frJxUxmZylthJ_LijMM > > * The semantics of 554 greetings: > > > https://mailarchive.ietf.org/arch/msg/ietf-smtp/NeHzVodzZX6kJFJ7lQhuP6gOpWA And I see I am not the only one to be confused by the use of a 5xx code instead of a 4xx code, or the reverse, for this. The background in the above references was indeed very interesting. It helps to bring me up to speed on the issue. Forty years! Well... We don't want to rush into these things. After all this whole electronic mail thing might just be a fad. :-) Thanks! Bob
