Quick article about re-writing the from address from postfix. First install the libsasl2-modules.
Add the following to main.cf
sender_canonical_classes = envelope_sender, header_sender
sender_canonical_maps = regexp:/etc/postfix/sender_canonical_maps
smtp_header_checks = regexp:/etc/postfix/header_check
</pre class="code highlight" lang="shell"></span class="line" lang="shell">Then create the files and their contents
/etc/postfix/sender_canonical_maps
/.+/ newemail@domain.com
/etc/postfix/header_check
From:.*/ REPLACE From: newemail@domain.com
Reload Postfix and test
mail -s “Test Subject” user@example.com < /dev/null
Check the mail logs to see if it’s successful. This trick is really useful if you use a 3rd party to relay email and they require some form of domain or address authentication.