Help – Disable Email notifications sent by wordpress plugins

I have some plugins installed in my wordpress, and now I received this email from my host service:

Your account has been unsuspended. It was suspended for mass mail. Please, note that mass mail is strictly prohibited by our Terms Of Service: http://www.hosting24.com/tos.php

You can send no more than 19 emails per minute (using PHP) and 9 emails/minute (using SMTP). Additionally, You are allowed to send up to 100 emails/hour from Your webmail account.

We are sorry for any inconveniences, but this is how the system works. We cannot remove this mass mail limitation as it would result in our mail server IP being blacklisted very fast. The server hosts hundreds of domains, and it is not possible to track everyone in real time so we must run this software to disable mass mailers.

I think the plugin “achievements” is sending too many emails, but I was thinking, if I have 100 users login in and posting things it will got suspended again if email notifications are beeing sent.

Theres any way to disable email notifications to users and not just for me?