mail -s "test email" someone@someplace.net
This is a test
.

and received some errors:

collect: Cannot write ./dfg7L1sl6t000695 (bfcommit, uid=501, gid=25): Permission denied
queueup: cannot create queue temp file ./tfg7L1sl6t000695, uid=501: Permission denied

Which I take to mean the mqueue and clientmqueue dirs in /var/spool

Just thought this would be helpful.

-thomas