I just want to caution you when setting up your emails in phpBB, it's fairly simplistic. If you are configuring it to run off a new mail server, you have to take a lot more into account. I made the mistake of thinking it was really simple when it wasn't.
Make sure you have all you authentication and configuration protocols in place. When I first set everything up any one who went to my forum their registration emails was landing in spam, because I didn't know anything about email.
Here are a few thinks to look up and make sure you have in place
Here's a few places to test your mail out to make sure it works properly..
1) Email Tester
2) mail Teter
Learn from my mistakes