GMail and unique email addresses

Who uses GMail can use almost infinite aliases, which are automatically enabled.
There are two things to keep in my mind.
First, dots don't count. For example, mario.rossi@gmail.com is the same as mariorossi@gmail.com and ma.rio.rossi@gmail.com .
Second, you can use email addresses like mario.rossi+forum@gmail.com .
All these email addresses refer to the same person. So, someone using GMail can register 1000 times with the same email address.
See here: http://mail.google.com/support/bin/answer.py?hl=en-ie&answer=10313 for dots.

Altough users can chose which email address to use, phpBB should clean it when calculating checksum.
So, before calculating the checksum, phpBB should remove all dots and everything between + and @ (including the +).