thorsten napsal(a): > The problem occurs on domain.tld == some_server1, which is a mail server. > domain.tld does backups for some_server2.tld and vice versa. > > so, domain.tld has: > mx 20 some_server2.tld (so, they do backup in case our server is down) > mx 10 domain.tld (this server. should deliver mails for domain.tld) > > if some_server2.tld (which for we are doing mx backup as well) is down, > our system keeps mails but does not deliver them. > > BUT: (and that's the problem) > > if one of us here on domain.tld wants to send an email to > some_server2.tld, then this problem with 'loops back to me' occurs > (since centos update). > > so IMO, it is correct having > > postmap -q some_server2.tld mysql:/etc/postfix/sql/transport > returning smtp:some_server2.tld > > and > > postmap -q domain.tld mysql:/etc/postfix/sql/transport > returning maildrop: > > so, if mails for some_server2.tld are arriving at domain.tld, it tries > to forward them via smtp to some_server2.tld which should be done via: > > smtp inet n - n - 25 smtpd > (from master.cf), AFAIK > > and EVEN, if I REMOVE the mysql entry for smtp:some_server2.tld, so it > should appear to postfix like every other domain in the world, postfix > finds a loop back to itself. > > And that's, what I don't understand. > > This configuration was already working and productive. > > thorsten. OK, so let's sum it up. Let's have domain1.tld and domain2.tld. domain1.tld has: 20 server.domain2.tld 10 server.domain1.tld domain2.tld has: 20 server.domain1.tld 10 server.domain2.tld on server.domain1.tld we need to have: domain1.tld within virtual domains or local domain domain2.tld within transport on server.domain2.tld we need to have: domain2.tld within virtual domains or local domain domain1.tld within transport David