Hi,
We are still having the problem in Plesk Version 18.0.41:
maillog:
Mar 4 10:23:01 d389.x-mailer.de postfix/smtpd[31206]: NOQUEUE: reject: RCPT from 139-177-176-177.ip.linodeusercontent.com[139.177.176.177]: 554 5.7.1 <
[email protected]>: Relay access denied; from=<
[email protected]>...