Postfix Host Or Domain Name Not Found Type A. Host not found Above is what I get when I send email to New Postfix Server. Boosting a couple questions mentioned in comments that might help figure out whats going on.
Your domain doesnt have an MX record to specify where mail should be delivered. Every host I check knows where the exchange server is but we still get this error. Name service error for namemydomaincouk typeA.
Alias_database hashetcaliases alias_maps hashetcaliases command_directory usrsbin config_directory etcpostfix daemon_directory usrlibexecpostfix debug_peer_level 2 html_directory no inet_interfaces all mail_owner postfix mailq_path usrbinmailqpostfix manpage_directory usrshareman mydestination myhostname localhostmydomain localhost mydomain mynetworks_style.
Can you add your etcresolvconf to the question. Have you successfully sent mail to other systems from this. Symptom in the log. Sudo service postfix restart.