bounced (mail for host2.domain2.net loops back to myself)

I find this error in my Mail Log:
Mail server delivery status bounced (mail for host2.domain2.net loops back to myself)

I find a solution on http://www.topology.org/linux/postfixloop.html

Like you can read in this tutorial, I have to add host2.domain2.net to the "mydestination" list in the /etc/postfix/main.cf file.

**But I wouldn't like to do it.
I'd rather to change this host2.domain2.net address and add another one to mydestination.
Is it possible? How?

For example, I change host2.domain2.net to host3.domain3.net and after that I add host3.domain3.net to my destionation.

Thank you very much