Hi
After a heck of a lot of investigating other possiblities I've found that the ability to sent email in Thunderbird via smtp.talktalk.net that disappeared when I upgraded from Win 8 to Win 8.1 (or, possibly when Avast updated) can be restored by switching off the scan of outgoing mail. Is this a widespread problem and is there a fix that allows this mail to be scanned sucessfully?
Thanks
