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I don’t think the problem you are having has anything to do with the MS Updates. But, then again, that may depend on the OS you are using … I dunno. I’m using W98SE fully patched and with the recent security updates. None of this caused me any problems with email nor avast! 
The problem is more likely with either Outlook, Outlook Express, or the email you are receiving. Those two are not very good email programs as far as security goes. 
Sorry, but that’s my 2 cents worth. Hope the issue is resolved for you very soon! 