what does this mean and what should I do about it? ???
welcome to the forums, srr! 
We need a little more info such as … which provider, OS, etc. so that we can better give you advice. If you could post a screen shot of the message or the complete message text, that would be helpful.
It sounds like you have the Outlook/Exchange provider enabled and you aren’t using MS Outlook (not express) or you haven’t started MS Outlook yet. That is usually why this message is displayed.
How do I post a screen shot of the Avast window?
http://forum.avast.com/index.php?topic=18612.msg157895#msg157895
please read this