> It would look like Ralf already showed you. But if you are sending to > example.org which has the two MX RRs, then there is no need to configure > transport maps. If you do use transport maps, the lack of brackets around > the nexthop means Postfix will use MX lookups when deciding which nexthop to > choose. > > You CANNOT specify multiple nexthops in the sense you tried to in your > original post.
Perhaps I left out a detail. There is actually a third mx in dns, which is THIS postfix machine. Although $ host -t mx domain.com domain.com mail is handled by 20 domain.com.bak-mx.smtpblah.com. domain.com mail is handled by 10 domain.com.pri-mx.smtpblah.com. if I do an axfr it is actually: domain.com. 3600 IN MX 10 domain.com.pri-mx.smtpblah.com. domain.com. 3600 IN MX 20 domain.com.bak-mx.smtpblah.com. domain.com. 3600 IN MX 90 POSTFIX.domain.com. So I want to avoid postfix sending mail for domain.com (a valid relay domain, actually our domain) to itself. I am not sure why a straight host lookup did not return the third mx when it is in dns. If this looks strange, it is due to the fact that this MTX's primary role is to relay mail FROM certain hosts which are configured to use this machine as their smtp server without using dns TO anywhere. However, I want to make sure that mail for our domain is also passed on properly back to one of the two mx's I mentioned, without looping back to this postfix. I hope that's clear...