Impossible to add mail contact with + sign

Precondition
User should have EDIT_OWN_PROFILE and EDIT_OTHERS_PROFILE

1. Go to Forum, open profile page
2. Press "Edit button" button
3. Press "Add contact" button and select contact type Mail
4. Enter email in format alla+blabla@gmail.com
5. Press "Save" button

Actual result: Error message "Please enter valid contact”, contact isn't added

Expected result: Contact should be added

Note: Please, add possibility to add Jabber, MSN, YIM, AIM contact types with + sign