Limit accounts to a single domain

You can create plugin that requires users to enter email from specified domain, and enable "user activation" requirement in admin, so they will need to prove they own valid e-mail by clicking activation link in e-mail message sent to them.

I don't have time to show how example plugin would look like, but I'll hopefully have something to show by end of the week.

Assuming you are using misago_docker, you should create directory named emailrestriction in the misago directory (same directory that contains manage.py file).

Inside this directory you will need to create two files:

__init__.py

default_app_config = "emailrestriction.apps.EmailRestrictionPluginConfig"

apps.py:

from django.apps import AppConfig
from misago.hooks import new_registrations_validators


class EmailRestrictionPluginConfig(AppConfig):
    name = "emailrestriction"
    label = "emailrestriction"
    verbose_name = "Email Restriction"

    def ready(self):
        new_registrations_validators.append(custom_email_validator)


def custom_email_validator(request, cleaned_data, add_error):
    email = cleaned_data.get("email")
    if not email:
        return
    if not email.lower().endswith("@mydomain.com"):
        add_error(
            "email", "You need to use an e-mail from mydomain.com to join this site."
        )

Replace mydomain.com part with your own domain.

Now, create file named plugins.txt in same directory that you've created emailrestriction directory in (the one that has manage.py file). Misago will use this file to read list of enabled plugins.

Inside of this file enter single line:

emailrestriction

This will make Misago load your emailrestriction plugin that you've just created.

Lastly rebuild Misago's Docker container using appctl:

$ appctl rebuild

That should do the trick.