Sorry for the late reply, thought I had already posted a message, thank you both for your quick response!

Our isp:s smtp-server hasn't been down for some time so I have a few mail in the /queue - directory. I have now changed to another smtp-server, Is there a way to force the queued messages to be sent now or do I have to wait an unspecified amount of time for the program to retry them?

Investigate the QCF files associated, they contain the next attempt time. More info on the format for this file is found here: http://community.pmail.com/forums/thread/150.aspx

there is a small utility called mercfix, which does the job :-)