If you want to accept delivery for one address only and reject all other adresses in the domain, you can do this with postfix's access table:
http://www.postfix.org/access.5.html A hint to transport tables: us...@example1.com lmtp:$HOW_TO_REACH_THE_MX us...@example1.com lmtp:[$HOW_TO_REACH_THE_MX] If you enclose the mx in [] postfix will just take the value as is and not force any MX lookups. Last but not least you could configure mail routing by sender if necessary: http://www.postfix.org/postconf.5.html#sender_dependent_relayhost_maps Best regards, Gerald > Am 12.09.2018 um 10:58 schrieb Jochen Bern <jochen.b...@binect.de>: > > On 09/11/2018 08:20 PM, Kai Schaetzl wrote: >> I have to disable mail acceptance for example1.com. >> If not, mail sent *from* that server (e.g. from a web form) to that domain >> will not leave the server. >> However, if I disable example1.com for mail dovecot lmtp will not deliver >> mail to this mail box anymore, although the mailbox still exists. > > First and foremost, you are describing a major routing problem *for the > MTA*. You want it to do local delivery (via LMTP) for > us...@example1.com, but forward mail addressed to foo...@example1.com to > that domain's current MX. Since MTAs usually(!) decide that based on the > *domain*, you have a need for some off-the-textbook tweaking right > there. And the config to make *dovecot* work as needed would need to > pick up from there. > > If we're talking postfix, my first idea would be to make example1.com a > virtual alias domain and set up a transport table with entries > us...@example1.com local: > # ... etc. etc. ... > example1.com smtp:$HOW_TO_REACH_THE_MX > (with $HOW_TO_REACH_THE_MX being anything from "use the official MX from > DNS" to "contact this internal IP on this port, *without* DNS lookups", > whichever your (internal?) networking necessitates). > > http://www.postfix.org/transport.5.html > > With a bit of luck, that might already "contain" the weirdness to the > point that neither the MX nor dovecot need config hacks. > > Regards, > -- > Jochen Bern > Systemingenieur > > www.binect.de > www.facebook.de/binect >