ValidateEmail gem is the ultimate email validator. It not only validates email address by Regex check but also optionally checks for the MX records.

gem install ValidateEmail

require 'rubygems'
require 'ValidateEmail'

You may validate an email address using Regex check by running:

ValidateEmail.validate("bvsatyaram@example.com")

You may also validate email address by both checking the Regex and also the MX record by running:

ValidateEmail.validate("bvsatyaram@noexisting.domain", true)

The ValidateEmail.validate method returns a boolean. So, we can have some thing as follows:

user.email = email unless ValidateEmail.validate(email)

B V Satyaram <bvsatyaram.com>