A question that I've seen in the past and ran across recently in a forum post is the issue of being prompted to pick your Outlook Profile when Dynamics GP attempts to access Outlook via the MAPI function library in Dexterity.
In the most recent case from the forum post (the short version of the story), the question brought up was that after login to Dynamics GP - the Outlook Choose Profile window was displayed.
A couple of thoughts on this situation.
The first thought was that this is normal. If the user isn't logged into Microsoft Outlook and access to email is necessary, then Dexterity/Dynamics WILL pop the Choose Profile dialog box -even if you don't have the Always Prompt for Profile option marked. This is expected and by design.
If you don't want this to happen, make sure that you are logged into Outlook before accessing a feature in Dynamics GP that would require accessing email.
The other thought was that this wasn't quite normal. Not exactly sure WHY this is happening on their system, though. On a typical Dynamics GP install, there isn't anything on logging into a company that would attempt access to the Dexterity MAPI library.
What if you have your home page set to display your email appointments and number of messages? No, that isn't it. While Dexterity can send emails, it cannot do anything (natively) with Outlook Tasks and cannot read or count emails. So in order for the home page to access these items, it actually uses COM to pull this information from Outlook.
So while I'm not sure if they have a customization that is doing this or if this is happening at a different point than what was suggested in the post - the answer is the same either way as detailed above.
Dynamics GP Developer Support