set virtual_alias_maps for aliases

roles/mail/templates/postfix-out/main.cf

@@ -39,12 +39,15 @@ smtpd_timeout = 1200s
 # "smtp" transport for outbound mail (bounces, ...). The latter
 # won't starve the former of delivery agent slots.
 relay_domains = ${indexed}domains cdb:/etc/postfix/domains-auto
-relay_recipient_maps = ${ldap}all-recipients ${indexed}virtual ${indexed}transport ${indexed}mailman_transport
+relay_recipient_maps = ${ldap}all-recipients ${indexed}transport ${indexed}mailman_transport
 relay_destination_recipient_limit = 1
 
 # Send each message to its target backend.
 transport_maps = ${ldap}all-recipients ${indexed}transport ${indexed}mailman_transport
 
+# resolve aliases
+virtual_alias_maps = ${indexed}virtual
+
 # Message size limit.
 message_size_limit = 15000000