I get the below warning in the mail log file.
postfix/trivial-rewrite[]: warning: relay_domains lookup failure
The mail server is working well without any issues. What can this error mean?
Running the test below produces the required output.
postmap -q "example.org" mysql:/etc/postfix/mysql/relay_domains.cf
Running with verbose confirms again that the query is successful and reading the correct table
postmap -v -q "example.org" mysql:/etc/postfix/mysql/relay_domains.cf