Problem Solved! The (slightly inaccurate) comment in my imapd.conf file is illustrative: defaultdomain: mailadmin.com ## ACHTUNG! The default domain must match the host name my hosts file contained the following entry: 10.0.0.2 mailadmin.com mailadmin I changed it to 10.0.0.2 host.mailadmin.com mailadmin That fixed the problem. Thanks for the help. ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html