[_ck_]

The “welcome email” (just really the password) message is sent via bb_send_pass which is sadly hard coded in registration-functions.php without any filters or actions to affect it.

The non-emailed registration success message is in the register-success.php theme template which can be edited.

However like all things bbPress, there is always a way around limitations, it’s just a bit more complex than it should be.

The “send password” trigger is done inside of the pluggable bb_new_user function which can be completely replaced, or supplemented.

To replace the function, you could copy it right out out pluggable.php and put it into a mini-plugin and edit away. The part that needs to be changed is near the end where it says bb_send_pass( $user_id ... ) You would basically copy how the bb_send_pass function works and replace the text inside.

It would be ever so slightly easier but probably more messy for the new user to send an additional email beyond the password email via the do_action('bb_new_user', $user_id, $password); trigger.