New version 0.5 is available. This is strictly a release to improve stability. I noticed that in previous versions it may crash after some amount of time particularly when you lose wifi and/or edge connectivity.
Just some clarification, the check button on the popup DOES NOT launch the mail client. What it is supposed to do is force the mail client to check the server for new messages. Also, I do not plan on retrieving other mail info such as subjects etc etc. This is strictly to notify you that mail has arrived as soon as it hits the server and then you use your mail client of choice to actually view the mail details.
For people that may be having issues and want to see what the program is doing or why you may be having problems, you can turn debug log on and view logging in a file called /var/root/Library/iMapIdle/iMapIdle.log. You can view this via ssh or using the vt100 terminal app on the phone itself...