Do all email providers ignore periods in front of @?

Question

I know that gmail lets a user insert as many periods as he/she wants in an email address before the @ sign. Gmail also lets users append the email address like this: userNam

Answer 1

This is really specific to gmail, but this applies to google apps for domain as well, so you would only be able to do it for @gmail.com

I wouldn't do this, this is only going to alienate your honest users and not prevent anyone determined to create multiple accounts.