How to disable SMTP ?

Hi,

I just found out on our overview screen following message:
Failed to send email notification via SMTP server mail, due to error: Unknown SMTP host: mail; nested exception is: java.net.UnknownHostException: mail

It looks that one of the developers set mail notifications. The problem is that I don't want to use SMTP in our TC. So I have 2 questions:
1. How I can disable this message?
2. How I can check who configure mail notification ?

Regards,
Michal