shoppergirl, try these instructions, in this order. I think this will solved your lost mail AND your errant spam email that keeps coming (I have a friend and there have been others here report a similar issue wherein they receive the same email like 400-1000 times over several days, and nothing else, at all).

1. At your carrier BIS website, Where can I log into my BIS account? - BlackBerryFAQ
remove the account associated with this issue, if you have more than one email registered there.

2. On your BB at Options > Advanced > Service Books. Clear any Service Books associated with the email address experiencing the issue, look for the address. Highlighted over that Service Book, press Menu to delete.

3. On your BB, with it powered ON, remove the battery, hold 30 seconds and replace the battery to reboot.

4. Go back to Options > Advanced > Service Book and confirm that Service Book is indeed deleted.

5. Return to your carrier BIS site and setup the email account you deleted earlier. At the BIS site, you might also need to find the "Resend Service Books" link, and perform that action.

6. You should receive a new Registratioon Message on your handheld. All should be fine now. At the least, you may need to remove the battery and reboot again, sometimes, for the Service Books to be installed.

7. Again, go to Options > Advanced > Service Book and confirm the service book has been installed.

Good luck.