An email message with an unknown domain won't be accepted/routed by Gmail.

Furthermore, an email from root@ any domain won't be accepted either, but my memory might be betraying me.

If you need those emails accepted to gmail, you need to change/mask them to a valid domain in the Internet.

Those restrictions are not specific to the gmail service, since the 90s that email routing rules have been tightened up by email service operators to fight spam.

An email message with an unknown domain won't be accepted/routed by Gmail.

Furthermore, an email from root@ any domain won't be accepted either, but my memory might be betraying me.

If you need those emails accepted to gmail, you need to change/mask them to a valid domain in the Internet.

Those restrictions are not specific to the gmail service, since the 90s that email routing rules have been tightened up by email service operators to fight spam.

For rewriting your outgoing email address in postfix, you have to do:

Add to your main.cf file:

smtp_generic_maps = hash:/etc/postfix/generic 

Now create a the /etc/postfix/generic file with the contents:

root@rene-desktop [email protected] 

It is however not enough creating the generic file, you have to tokenize it for postfix to use it. Do then to create the generic.db file:

postmap /etc/postfix/generic 

Now restart postfix and you should have that email mapping in place.