[Closed] Email error with Virgin/Norton

Ive been having a nightmare day with emails and errors.

everythings been great up to today and no settings have been changed.

Every email ive sent today comes up this pop up from Norton.

Your email message was unable to be sent because the connection to your mail server was interrupted. Please open your email client and re-send the message from the sent messages folder.

Anyone else having problems and how I go about fixing it? The thing is its only a Norton pop up box telling me this and nothing in Outlook saying there is a problem about undelivered emails?

Thanks in advance

Smudge