The remote host is missing an update as announced via advisory SSA:2005-310-06.

https://secure1.securityspace.com/smysecure/catid.html?in=SSA:2005-310-06

New imapd packages are available for Slackware 8.1, 9.0, 9.1, 10.0, 10.1, 10.2, and -current to fix an alleged security issue. It appears that there is a buffer overflow in the 'mail_valid_net_parse_work' function, but that the function may not be used (i.e. is dead code).