Troubleshoot Missing Admin Emails + retrieve missing ones

Hi! I have two PHPBB forums under the same general website. Both of them have required admin approval before users are confirmed. I need to be receiving the email stating that a new user has registered, (the email includes a special voice confirmation link also) For some reason, SOME emails are coming through, but not all. Many users have complained that we haven't approved their account. The website is very new, so there are only maybe ten missing emails from both forums. This job requires that you: a) retrieve the missing emails to the admin, (including links to voice confirmation) b) prevent this from happening in the future. I'm not sure if this changes anything, but the emails were sent via a catchall account (ie even though the administrative emails for each forum were forum1(at)[login to view URL] and forum2(at)[login to view URL] , those email addresses didn't exist, rather everything was "caught" by admin(at)mysite.com. I have since changed this and actually created those email addresses.