This is one common Postfix error when setting up mail accounts. You receive a message with subject: “Undelivered Mail Returned to Sender” and you find the following lines in its content:

                   The mail system

: mail for chrfisioterapia.com loops
    back to myself

It’s weird, but it occurs when the e-mail MX server points to our server, we may have added the virtual mailbox or alias but we have not added the corresponding line to the mydestination directive in /etc/postfix/main.cf so we must add our domain there.

For example:

mydestination = localhost totaki.com mydomain.com

Then, just restart or reload postfix and the error must be gone. (You must re-send the emails).