How to force qmail to process the outbound queue

If/When you get a DNS problem or other network issue that causes the queue to fail it will fill up at a fair speed.  Use the following to tell qmail to make another attempt at sending.
/var/qmail/bin/qmail-tcpok

Or you can do this.

Run ps axl and find the process id (PID) for qmail-send
Run kill -s ALRM pid
To find out if there are any messages in the queue use

qmail-qstat or qmail-qread