I’m currently using SquirrelMail for my webmail services, and it is working very well, expect Attachments are sometimes a problem. I have used IMP and Horde on a Liux Box, at it seemed to handle attachments better than SM. Has anyone configured and used Horde and IMP on Panther Server?
there are limits on the size of file set by sm. maybe you overlooked this.
also make sure there is no size limit on the mail file as well as the email it self.