Change Mailer Daemon email (solved)

Hi

System: debian 6 with postfix.

I updated my /etc/aliases file to forward all root messages to a new email. However I still recive mail from "Mail Delevery System" (MAILER-DAEMON@ to my old email that I had for root before. How can I change this? All the other system mail goes to the my new email.

Update: Solved by HoopyCat in chat:

My issue had nothing to do with postfix, it was the app that sent out the mail that had the wrong email.

Regards

Martin