From the Email Notifications (Home -> Members Area -> My Account -> Email Notifications) menu, enable / disable:
If enabled, users will receive emails about the new messages received on the site.
Select whether to receive email notifications from the website.
Note: Important emails regarding account status and sale / purchase notifications will still be sent.
Include closed, relisted, no sale, as well as approved and suspended listings notifications.
Include offers module related email notifications: new offer, counter offer, offer accepted, offer declined, offer withdrawn.