Open Outlook Express, and click Tools Then click on Accounts Then click on your email connection and click Properties Then click Advanced On this screen remove the checks from the boxes This server requires a secure connection for both Outgoing mail (SMTP) and Incoming mail (POP3).
OK everyone- really sorry to have pestered you all.
In the end I finally got through to my Broadband supplier on the phone - they quickly pointed out that I had an email stuck in my outbox which Express was trying to send everytime. All I had to do was to delete it!
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