I\'m writing a program that should display the amount of unread sms, mms, phone calls and emails. It was quite easy to find how to query for sms and phone calls (I used the
Unfortunately that is going to be difficult because you don't know which application(s) the user uses for eMail and there is no shared database or provider.
I suggest you make a list of the most popular eMail apps, implement the counter separately and add the numbers.
I'm guessing Google's GMail and EMail apps are amongst the most popular and I've used Nitroid's Touchdown before EMail had exchange support.