As you’ve got the Feb 09 08:54:24 ubuntu-mail-receiver postfix/master[1]: daemon started – version 3.5.6, configuration /etc/postfix log, but you don’t get a rejected email, it makes me think the problem could be in the DNS section of the guide.
As you’ve got the Feb 09 08:54:24 ubuntu-mail-receiver postfix/master[1]: daemon started – version 3.5.6, configuration /etc/postfix log, but you don’t get a rejected email, it makes me think the problem could be in the DNS section of the guide.