Module adds a '3D' before email address when subscribing

Tried to subscribe an authenticated user whose email is name@domain.com.br to a mailing list using the form at user/X/edit/mailman_manager.

The confirmation message says:

"We received a request from name@domain.com.br to subscribe the addres 3Dname@domain.com.br to the mailing list"....

The message was sent to the wrong address (3Dname@domain.com.br). I only received it because I have a 'catch all" email address configured at domain.com.br.

Mailman version I'm using is 2.1.9.cp2.