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: user1@example1.com lmtp:$HOW_TO_REACH_THE_MX user1@example1.com lmtp:[$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.bern@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 user1@example1.com, but forward mail addressed to foobar@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 user1@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
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