Hey guys,
We just upgraded from version 3 to 4 and everything was running fine until we received a few calls about some clients not being able to POP there email.
Quickly we were able to find out it was only effecting outlook 2007.
We tried removing the POP abuse detection but had no joy.
Log files revealed an error 'Closing transmission channel: too many bad commands'
I then checked the POP3 settings under 'Settings>Protocol Settings' and found the Max Bad connections was set to Zero.
After raising it to 2, everything seemed to be working fine.