app/validators/email_validator.rb
require 'mail'
class EmailValidator < ActiveModel::EachValidator
def validate_each(record,attribute,value)
begin
m = Mail::Address.new(value)
# We must check that value contains a domain and that value is an email address
r = m.domain && m.address == value
t = m.__send__(:tree)
# We need to dig into treetop
# A valid domain must have dot_atom_text elements size > 1
# user@localhost is excluded
# treetop must respond to domain
# We exclude valid email values like <user@localhost.com>
# Hence we use m.__send__(tree).domain
r &&= (t.domain.dot_atom_text.elements.size > 1)
rescue Exception => e
r = false
end
record.errors[attribute] << (options[:message] || "is invalid") unless r
end
end