sendmail, DNS and clientqueues

[Marko Leer]

Hi all,

I'm running a web/mailserver on a FreeBSD 4.8 box and I combine these
two functions with PHP. To increase performance I deliver the
emailmessages directly to the sendmail queue.

Sendmail these days has two queues in /var/spool. As I understand it
sendmail runs two daemons; one that's listening on port 25 for mail to
send and another one that is monitoring the queue.
If a message arrives for sending, a connection is attempted at
port 25 of the localhost. This is a notourious slow operation on my
dedicated server [I suppose because there's no named daemon running on
the box; this is a sendmail defaultassumption that I don't know how to
hack]
If this connection fails [or the hostname of the sender cannot be
resolved] this message is filed in /var/spool/clientmqueue instead of
/var/spool/mqueue.

All messages from the webapplications end up in clientmqueue, which is
not constantly monitored.
The sendmail -q command sends all queued messages in mqueue.

Now I've been wondering for some time
- if the assumptions above are correct
- why this localhost lookup is slow
- how to force sendmail to send the messages in clientmqueue
- if there's a sendmailusersmailinglist anywhere on the web where this
questions probably should be posted.

So far I haven't found any information on these specific issues so ANY
clues are greatly appreciated.


TIA,

=:0]

Marko