Daniel Miller: > This question is actually two questions - neither of which are > Postfix-specific but email-generic - but this list is the best resource > I have to ask such questions. > > First - I've been contributing to "Project Tarbaby", which means I have > a pair of secondary MX records below my primary which accept anything > they get - and those get used to build DNS blacklists. Properly > configured hosts talk to my primary server without issue. The only > question here is - does anyone have an objection to what I'm doing with > this?
This is unsafe, because the connection to the primary MX may fail for all kinds of reasons, including a temporary network outage somewhere far away on the Internet. > Is the method for working with primary vs secondary MX records clear - > at least clear enough that my tarpit setup should work? Or is there > enough of a grey area that this setup is doomed to failure regardless? Tricks with MX-priority spamtraps share the problem that they make assumptions about the behavior of all legitimate MTAs. For a related approach, see, for example, "nolisting". Wietse