UPDATE
[2009-09-15 14:37:13 | Lars Rohrbach]
Staff have isolated and fixed the problem causing intermittent login failures to the IMAP web interface on webmail.eecs. A few people reported trouble accessing their mail using clients such as Outlook or pine; that is fixed as well.
Any further problems accessing the EECS IMAP server should be reported to help@eecs.
Technical note: it appears that there is a bug in the LDAP proxy code, and we now have a workaround in place.
Resolved as of 2009-09-15 12:45:00