Hi,

In Odoo, the records under Settings → Technical → Email → Notifications come from the mail.notification model. These are created every time a notification is sent, such as an email, chatter message, or activity reminder. They are not business-critical data like invoices or sales orders but rather logs that track who received which notification.

It is generally safe to delete old notification records, especially if they are consuming a lot of space, as in your Odoo.SH environment. Doing so won’t remove the actual emails, chatter messages, or activities, but it will remove the delivery logs. However, there are some side effects: message read/unread status might be affected, pending emails will no longer be retried, and any audit trail of notifications will be lost.

The best practice is to delete old notifications in bulk, for example, anything older than six months or a year, instead of clearing everything at once. This can be done using a scheduled action so the cleanup happens automatically. On Odoo.SH, this helps reduce database size, improving performance and lowering hosting costs.

Hope it helps