Can't download new mail messages

Have had this problem a couple of times in the past with my BellSouth account and eventually got it worked out but I'm stumped this time.

Incoming mail goes to my iPhone just fine.

I can send mail but cannot receive it.

Library/preferences/com.apple.plist file does not exist

Highlight my BellSouth account in mail and right click / get account info - it shows all the new messages on the server

No lightning bolt beside any of the accounts - all are online . Have taken all mail accounts offline and then back online - ng

Have done a hard restart and even a SMC reset - nada

Running OSX 10.8.3

Everything was fine until 5 days ago. Haven't change any settings or added new software but have been having errant shutdowns due to a kernel panic issue...

Have checked all relevant forums, tips trick and magic wands - ng

Running out of hair to pull out 😠