Email Validation and Prefix Periods

[eluser]Unknown[/eluser]
I am validating an email address on whether a record exists already in the db.

My problem is that gmail allows periods in a prefix, and any smart person would know that [email protected] and [email protected] would work and belong to the same gmail account.

Would you say it's safe to strip all periods from the prefix on all email accounts, or would this not be safe and is dependent on the email service?