On 21/01/15 12:50, Klaus Ethgen wrote: > I go back to the list with that discussion... > > Am Mi den 21. Jan 2015 um 13:17 schrieb Jeremy Harris: >> On 21/01/15 12:13, Klaus Ethgen wrote: >>> Am Mi den 21. Jan 2015 um 13:09 schrieb Jeremy Harris: >>>>>> How do they receive bounces? >>>>> >>>>> What do you mean, how do they receive bounces? Bounces are not different >>>>> on that level. They are just regular mails. >>> >>>> If they have no MX or A, where am I to send a bounce to? >>> >>> To the sender address as you do with MX. > >> ... and this sender address has no MX, yes? > > Well why should it? It can but it is not mandatory. As it is for every > other e-mail address. > > I think you are a bit confused from how mails are send at all. > > First there is DNS. In DNS you have usually an A record and/or an MX > record. The mail server uses is to MX or A (in this order) to find the > server to send mails to. > > That is all, MX is used for. > > Something completely different is a bounce or a bounce mail. A bounce is > just a normal mail with two exceptions: > 1. It is created by the mailserver > 2. It has no sender address. (Envelope(!), nothing else is relevant for > the server. > > However, as all other mails, it has an recipient address that is the > envelope-from address of the original mail that causes that bounce.
Thank you, but I do know about email. For me, operating as an MTA: if the envelope sender address has a domain for which there is no MX or A record in DNS, then I cannot send a bounce. For me, as the administrator of an MTA: if my MTA cannot return a bounce to a sender then I cannot maintain overall reliability of email, in the notification of error conditions. Therefore I do do wish to take responsibility for such a message. -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
