[MM3-users] How to disable subscribe by mail in mailman3?

Hello,

I've setup a mailman3 for an organization. Organization members are authenticated by an LDAP backend and can thus use the web UI to subscribe.

To avoid unnecessary moderation, I'd like to disable subscription by mail but still allow subscription through the web interface.

(I've already hacked some code to dissallow subscribe by mail through posteros.)

Regards, Thomas