in reply to sendmail *grumble*

sendmail -q

from the command line causes it to process the queue once, then exit. Add the -v switch to make sendmail chattier while it does it. Normally a sendmail daemon only queues under difficulty, it should process the mail immediately without queuing unless it has been configured to do so. You can add a time argument to -q:

sendmail -q1h

processes the queue every hour.

Check out for further documentation. You may have to invoke the -d debugging switch to see what sendmail sees.