Regular expression for e-mail Posted on June 16th, 2005 by

Regular expressions can be very useful and efficient if used properly. For a while now in some of our applications we have been using the following regular expression to check e-mail addresses for proper formatting.


This will ensure that the user has entered a properly formatted e-mail address such as



  1. Ryan Rud says:

    Don’t forget about arpa!! The expression should be ^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*\.(([a-z]{2,3})|(aero|arpa|coop|info|museum|name))$

  2. […] We discovered a small bug in our old regular expression for checking valid e-mail addresses. When a user tried to use an address with capital letters on a form, it failed to match the regular expression. We updated the regular expression to account for capital letters anywhere in the e-mail address. […]

  3. Ryan Rud says:

    This regular expression has been updated to check for capitalization in e-mail addresses.

  4. John Michael Pierobon says:

    This is fantastic.
    But, how do you validate for an address of
    the following format