But should post hang even if send/post is improperly invoked? Maybe the
contexts in which they operate is sufficiently complex and so dependent on
external systems that never hanging is an impractical goal.
In a perfect world, no, send/post should never hang. But we never got good
details on what was going wrong there. I believe you said running it with
-snoop returned no messages, it still was silently hung.
If you're using the "smtp" or "sendmail/smtp" MTAs, there should never be
a hang. There may be a network timeout along the way, but you should see
some notification with -snoop as to what it is doing (the timeouts could
be up to a few minutes, depending on the operating system). I could maybe
see problems contacting a DNS server, but you would think that would
show up in others ways (and even then, eventually you'd get an error
message).
If you're using "sendmail/pipe", all bets are off.
If you have a setup which uses a custom postproc, again, all bets are off.
--Ken