add-log-mailing-address is a variable defined in `add-log.el'.
Its value is

Email addresses of user, for inclusion in ChangeLog headers.
This defaults to the value of `user-mail-address'. In addition to
being a simple string, this value can also be a list. All elements
will be recognized as referring to the same user; when creating a new
ChangeLog entry, one element will be chosen at random.

You can customize this variable.