In config, I've defined allowed relay_domains /main.cf ... relay_domains = DDDD1.com DDDD2.com ... DDDDn.com
and also use transport_maps=lmdb:/usr/local/etc/postfix/tranports where currently, each relay domain is /transports ... DDDD2.com relay-vpn:[internal.DDDD.com]:12345 DDDD1.com relay-vpn:[internal.DDDD.com]:12345 ... DDDDn.com relay-vpn:[internal.DDDD.com]:12345 ... Can the relay_domains array itself be correctly used as a lookup in a lookup table? I'd 1st guess that some form of regex table could be amenable, in effect /transports.pcre ... /$relay_domains/ relay-vpn:[internal.DDDD.com]:12345 ... ? Reading http://www.postfix.org/regexp_table.5.html http://www.postfix.org/postmap.1.html http://www.postfix.org/pcre_table.5.html body patterns can certainly be referenced as match variables ( ${1}, ${2}, etc ), but I've so far missed any mention of use of main.cf data. Of course there are other ways at this ... putting the relay_domains in an SQL DB, and using an SQL lookup , etc. The reference to 'flatfile' main.cf's data would simply be, in this case, convenient.