diff --git a/app/models/email_address.rb b/app/models/email_address.rb
index b4e390679..28ca9c6b1 100644
--- a/app/models/email_address.rb
+++ b/app/models/email_address.rb
@@ -20,8 +20,6 @@
 class EmailAddress < ActiveRecord::Base
   include Redmine::SafeAttributes
 
-  EMAIL_REGEXP = /\A([^@\s]+)@((?:[-a-z0-9]+\.)+(?:(?:xn--[-a-z0-9]+)|(?:[a-z]{2,})))\z/i
-
   belongs_to :user
 
   after_update :destroy_tokens
@@ -32,7 +30,7 @@ class EmailAddress < ActiveRecord::Base
   after_destroy_commit :deliver_security_notification_destroy
 
   validates_presence_of :address
-  validates_format_of :address, :with => EMAIL_REGEXP, :allow_blank => true
+  validates_format_of :address, :with => URI::MailTo::EMAIL_REGEXP, :allow_blank => true
   validates_length_of :address, :maximum => User::MAIL_LENGTH_LIMIT, :allow_nil => true
   validates_uniqueness_of :address, :case_sensitive => false,
     :if => Proc.new {|email| email.address_changed? && email.address.present?}
diff --git a/app/models/setting.rb b/app/models/setting.rb
index a7b763503..05daba9d6 100644
--- a/app/models/setting.rb
+++ b/app/models/setting.rb
@@ -188,7 +188,7 @@ class Setting < ActiveRecord::Base
     if settings.key?(:mail_from)
       begin
         mail_from = Mail::Address.new(settings[:mail_from])
-        raise unless EmailAddress::EMAIL_REGEXP.match?(mail_from.address)
+        raise unless URI::MailTo::EMAIL_REGEXP.match?(mail_from.address)
       rescue
         messages << [:mail_from, l('activerecord.errors.messages.invalid')]
       end