I checked cron and the clearopensmtp job is there.
I ran clearopensmtp by hand and it did not clear the file /home/vpopmail/etc/open-smtp
I cleared the open-smtp file by hand and tried to send from my laptop rather than sqwebmail and still no dice.
I have yet to read the docs for clearopensmtp. That may not be working correctly due to misconfiguration. Now that I know where to look I should beable to knock this one out quickly.
I might guess that your /etc/tcp.smtp is not getting compiled into /etc/tcp.smtp.cdb.
Usually this is done with '/usr/sbin/qmailctl cdb'.
I am not familiar with roaming users but I believe that this tcp control system is used.
See http://cr.yp.to/ucspi-tcp/tcpserver.html
This is of course assuming you are using ucspi-tcp and probably daemontools.
-Alex