Rob has hit the nail on the head
/etc/services
_change_ 'pop-3' to 'pop3'
don't add the pop3 line in addition to pop-3 (this may only be my experience) as pop3 would not work if listed below pop-3.
the /etc/services file appears to be updated when you make changes via the e-smith manager so until a fix is issued or somebody (Rob Fantini?) comes up with a custom template we may need to keep editing the /etc/services file. I haven't figured out the custom-template system fully yet ;(
We have email again!