The nessage is:
The server for account "Talk21" returned the error "[UNAVAILABLE] internal server error (#IS6530)." Your username/password or security settings may be incorrect. Would you like to try re-entering your password?
Its a BT Yahoo Talk21.com account. I have had this problem for months but recently its every minute or so making it un-usable really. BT Yahoo mail couldn't help. all the settings are as they recomment for IMAP / SMTP.
Any ideas welcome, before I ditch this email account!