Revert "remove reject_unlisted_recipient"

This reverts commit 67452af5.
1 job for !1248 with 5642-fail2ban-fails-to-detect-failed-dovecot-login-attempts-immediately in 7 minutes and 59 seconds (queued for 14 seconds)
detached
Status Job ID Name Coverage
  Syntax
passed #7450
syntax:lint

00:07:59