How to configure a fixed Sender Address for all E-Mails?

To workaround the error: "550 5.7.1 Client does not have permissions to send as this sender" needs the option in the Plesk panel to set header From.
In case using a user account for SMTP relaying via external Mail server.

At the moment this is only possible through the manual configuration of canonical maps in the Postfix.

1. Add to /etc/postfix/main.cf
   sendercanonicalclasses = envelopesender, headersender
   sendercanonicalmaps = regexp:/etc/postfix/sendercanonicalmaps
   smtpheaderchecks = regexp:/etc/postfix/header_check

2. Rewrite the envelope address from the email originating from the server itself:

   vi /etc/postfix/sendercanonicalmaps

   /.+/ newsender@address.com

3. Rewrite from the address in SMTP relayed e-mail:

   vi /etc/postfix/header_check

   /From:.*/ REPLACE From: newsender@address.com

4. Generate map:

   postmap /etc/postfix/sendercanonicalmaps

   postmap /etc/postfix/header_check

5. Restart postfix

   systemctl restart postfix