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phpregexemailemail-validationgoogle-account

How to filter/remove Google Email ALIAS with PHP?

I can create the unlimited email alias in Google Accounts (Gmail), ref: http://www.gizmodo.com.au/2014/09/how-to-use-the-infinite-number-of-email-addresses-gmail-gives-you/

But I need to filter email address to avoid that a user uses the same original email for the register in my application.

I would like to know if have anything to solve this? or my unique option is filtering with regex?

Solution

  • I don't agree with the comment outright stating that you shouldn't strip out the "filters" (e.g. user_email+some_filter_to_flag_incoming_messages@example.org). "Your use cases aren't the same as my use cases" and so on.[0]

    tl;dr: The regex pattern you're looking for is: '(\+.*)(?=\@)'

    Explanation:

    To start, write a regex that matches the literal '+' sign and any single character, any number of times:

    '(\+.*)'

    When replacing this pattern with an empty string, this will turn [email protected] into tristan. If you decide to split on the @ symbol, congrats, concat the resulting string to '@' + domain.TLD to this and you're done. I mention this in case you've already split the e-mail address and it's just hanging around anyway.

    If you're not splitting the user-email address on the @ symbol, you need to use a "positive look-ahead" (match this pattern if it's proceeded by this thing I specify) to tell your match when to stop (so we don't take away too much):

    '(\+.*)(?=\@)'

    with this in place, we get [email protected]. Hooray, that wasn't actually so rough.

    [0]: In one of my applications, I store the original filter-containing e-mail address that users give me for communications, but track filter usage and consider the canonical account (referenced-internally) to be the version without the filter (e.g. [email protected]). I do this to make it easier for users that opt-in to be located by e-mail address to search for each other.

    I understand why people use aliases/filters:

    • they give the illusion that they can be used to track spammers (as if an e-mail harvester wouldn't remove the filter before selling a list)
    • they're useful in routing emails or triggering events (e.g. sending a text when you get an e-mail from [email protected])
    • the "omg i can do this?" factor

    Which is all to say, "I get it, people like filters," but there's valid reasons as an application author or a company to make note of them.