Filterer: Unless of course you wanted a secure connection....
Agreed, but first you need to check your ISP supports POP3 over SSL.
I had this setting turned on for quite awhile and it wasn't an issue until ihug was being crippled under huge spam loads (~ 3 years ago I think) that they put in IronPort. Since they didn't utilise the SSL option of IronPort, if you tried to connect under SSL, it would come up with a "SSL cert not valid" (or similar) error.
Turning off the option stopped my email client attempting SSL and all was well with the world.