sender_dependent_relayhost_maps works except that the other settings affecting the relay aren't conditionalized by the defined relayhost maps. In this case the relayhost for the externally relayed "business" domains requires TLS and authentication while the relay for the local domain (being the local Postfix) does not.
So my follow-up question is this: is it possible to affect other relay parameters such as smtp_sasl_auth_enable or smtp_tls_security_level with the sender_dependent_relayhost_maps? Ville
