ref: a28263f7b282a639e6da2f2a3ede794a4833807f
dir: /sys/lib/sysconfig/auth/files/rewrite/
# convert source domain address to a chain a@b@c@d... @([^@!,]*):([^!@]*)@([^!]*) alias \2@\3@\1 @([^@!]*),@([^!@,]*):([^!@]*)@([^!]*) alias @\1:\3@\4@\2 # convert a chain a@b@c@d... to ...d!c!b!a ([^@]+)@([^@]+)@(.+) alias \2!\1@\3 ([^@]+)@([^@]+) alias \2!\1 # all mail plan9\.bell-labs\.com!(.*) | "/mail/lib/qmail '\s' 'net!plan9\.bell-labs\.com'" "'\1'" .* | "/mail/lib/qmail '\s' 'net!plan9\.bell-labs\.com'" "'&'"