I had a similar problem some couple of years ago wherein I was using Outlook (not Outlook Express) for my BT e-mail and incorporated Sky e-mail. It functioned with the Sky e-mail initially and then started to come up with error messages similar to yours. I removed the Sky e-mail account from Outlook and it functioned OK. I associated the problem that that being a Microsoft product it would not allow the integration of A N Other product. With regard to google-mail I have that as a separate entity to Outlook and do not have a problem.
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