Hi,
I just installed a mailman3 instance, even haven't announced to anyone yet, there are a lot of spam robot accounts registering into my system.
(See https://nextcloud.slat.org/index.php/s/WWHo7F3igYxn8LY for screenshot)
I really have no idea how the robots find my system since I haven't told anyone the ip or URL of my mailman instance. And, they're registering on the system, not the mailing list since I have only one list for testing now and it wasn't assaulted by spam yet.
No matter what, what I want to ask is that, is there a way to either
just let users join from email (lists-join@lists.url) instead of registering on the mailman instance? or
use a scheme like CAPTCHA to reduce the successful opportunity of robot registering?
Any help is appreciated!
Franklin