> Hello everyone. We migrate our infrastructure postfix to exim. However,
> an old application (mail to fax) uses a domain "[ip-address]". This
> illegal domain works with postfix and not with exim. I try to disable
> "dns_check_names_pattern" but my mail is rejected.
>
> My test :
> ---
> echo "" | mutt -a "/tmp/test.pdf" -- infos@???
> Error sending message, child exited 1 ().
> Could not send the message.
> ---
>
> Do you have any idea?
>
Yep, check the documentation about domain literals:
allow_domain_literals Use: main Type: boolean Default: false
If this option is set, the RFC 2822 domain literal format is permitted in email addresses. The option is not set by default, because the domain literal format is not normally required these days, and few people know about it. It has, however, been exploited by mail abusers.
Unfortunately, it seems that some DNS black list maintainers are using this format to report black listing to postmasters. If you want to accept messages addressed to your hosts by IP address, you need to set allow_domain_literals true, and also to add @[] to the list of local domains (defined in the named domain list local_domains in the default configuration). This “magic string” matches the domain literal form of all the local host’s IP addresses.
