Prevent Postfix to post directly to Host when no MX

[EddyInterPC]

I have many deferred messages due to domain that have neither MX record neither responding local SMTP server.

What on earth is the way to tell Postfix to not try to post directly to A record when there is no MX records for the domain ??

[jledhead]

I don't think postfix has a builtin way to not send directly to the A record.
reject_unknown_recipient_domain
and
reject_unknown_sender_domain

I believe are the only valid, related commands. but they will check for a valid mx or A

you can have a look here and see if you can find anything else, or join the mailing list. when I was an admin for postfix the mailing list was the most crucial help I got, and folks there are very very helpful, as they either wrote the book or wrote the code