I have an ArchLinux server with postfix, postfixadmin, dovecot, roundcube, quotas and spamassassin running fine.
The server is the main (not a backup or forwarding) of 3 virtual domains: domone.example
, domtwo.example
, and domthree.example
.
The server is running perfectly, has no problems and is in production. All three domains can send and receive mail from and to the outside, and between them.
Now I need to change it so that nothing changes for domone.example
and domtwo.example
but domthree.example
should now behave like this:
domthree.example
can receive mails from outside and fromdomone.example
,domtwo.example
anddomthree.example
.domthree.example
can send mail only todomone.example
,domtwo.example
anddomthree.example
, but not to the outside or other domains.
I have been searching for 3 days, I know it is related to relay_domains
and virtual_domains
, but I can not find the solution.