On Wed, Aug 13, 2025 at 08:46:50AM +0200, Frank Richter via Exim-users wrote: > Am 12.08.25 um 17:01 schrieb Evgeniy Berdnikov via Exim-users: > > > How can I achieve that exim gives a '550 Unrouteable address'? > > You should NOT reject mails with 550 status on temporary DNS failures > > unless you consider occasional rejects/bounces as acceptable situation. > > Your’re right. I didn’t recognize the SERVFAIL, for gmial.com. When DNS > returns NXDOMAIN, > exim’s behaviour is correct: 550 … > > Now, (how) can I change this message '451 Temporary local problem - please > try later'? > This causes questions to me: Please fix your local problem :-)
If you are relaying messages to existent and valid domains, temporary DNS failures for them should not be a problem: mail should be delayed and wait in queue for next attempt. It does not matter whether you keep this queue on your server or use passthrough delivery, when code 451 is returned to sender. No problems should be visible for users. If DNS *permanently* returns ServFail for a domain, which has MX records pointing to your server, and your configuration *allows* relaying for this domain, then you claim to be responsible for traffic to this domain and should handle those DNS failures. It's really YOUR PROBLEM. Assuming nobody should run as open relay for spammers. So, it sounds strange to ask how to change diagnostic message "451 Temp..." instead of real work to resolve this DNS or configuration issue... -- Eugene Berdnikov -- ## subscription configuration (requires account): ## https://lists.exim.org/mailman3/postorius/lists/exim-users.lists.exim.org/ ## unsubscribe (doesn't require an account): ## [email protected] ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
