I had it in my head that LDAP could be used to enable the Verify Receivers option. I see that I was wrong. I find this unworkable in our current setup. I am frustrated that while the Proxmox is clearly aware of every group and email account using LDAP, it is not configurable to check this LOCALLY CACHED list during SMTP sessions, to prevent receipt of mail for which there is no valid destination. Further, even locally-stored user-created lists cannot be used as a Verify Receivers resource.
This is the best way to keep undeliverable queues empty. Simply deleting the mail after receiving it is wasteful of the bandwidth it took to receive, and irresponsible towards the sender. Accepting mail and dumping it secretly is a poor way to operate a mail server, and sending NDRs after the fact will only lead to spam relay abuse.
Isn't there any way to do this that will allow me to a) have other mail gateways in the chain, and b) avoid turning on NDRs on any internal servers?
This is the best way to keep undeliverable queues empty. Simply deleting the mail after receiving it is wasteful of the bandwidth it took to receive, and irresponsible towards the sender. Accepting mail and dumping it secretly is a poor way to operate a mail server, and sending NDRs after the fact will only lead to spam relay abuse.
Isn't there any way to do this that will allow me to a) have other mail gateways in the chain, and b) avoid turning on NDRs on any internal servers?
