[Zope] problems using sendmail-tag

Hi everybody. I have a form that calls a sendmail tag to send user-feedback to a specific email-adress. When I try to send mail I always get the error: Recieved error code 553 from SMTP: 553 ... Domain name required I know that this error occurs if the user is not allowed to send mail from that host. The strange thing is that my zope runs under user 'zope'. But if I telnet to port 25 (sendmail) as user 'zope' I can send mail?? Any Ideas? TIA Philipp Dunkel ******************************************** * Philipp Dunkel ICQ# 60149094 * * zReal Productions * * meet me at DALNet chan #phidu * ********************************************