What kind of notification do you need?

Nuxeo does have a notification already integrated. If you configured the mail settings for your Nuxeo deployment (look here how: https://doc.nuxeo.com/display/ADMINDOC/Setup#Setup-MailSettingsmail-settings or via the Admin Tab and then Setup) you just need to click on the alert/notification icon for the folder/workspace you need updates/alerts/notifications.

If you need notifications (via e-mail) to be received by a Nuxeo repository you may consider the IMAP addon.

Please clarify.