Hi.

Basically notifications work in two ways:

Instant Notification

This is sent if the user has "instantly" selected in the subscription tab on his profile .

Askbot can be configured to use Celery to queue the email sending task, so the issue of posting taking a long time is solved this way, information about this in the oficial documentation.

If you don't use celery your site may take a long time to post new content because the emails will be sent synchronously and if you have many users with this option selected, an email will be sent to each subscribed user at that time, so that's why it takes a long time to post content.

Daily/Weekly Notifications

This is done with the send_email_alerts management command as a cronjob, this cronjob needs to be configured to make it work.

There is a sample cronjob file on the repository this cronjob needs to be run daily and it will send the notifications according to the user's configuration.

Note: in this cronjob command you might want to include Django's clearsessions management command to delete old session data and save space on the database (info here)