[SOLVED] 2 MX with one Mail GW

vusald

New Member
Apr 16, 2023
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I have a question about setting up 2 MX records rather than a question about Proxmox Mail Gateway, which works good in my environment.

You know the trick, when you have 2 WAN IP address you don't need to have 2 DNS Server like Master and slave. You can NAT both to same internal IP and "the world would think" you have 2 DNS Sevrers when you have just one

Can I do same trick with mail submission. ?

What If I have 2 WAN Ip and would like to have 2 MX records (single domain) but with one Mail gateway.
I'm just curious about hostname of Mail GW, because as far as I know it should be the same as your MX record.

I've done it before but I always had 2 Mail Servers, not one.
 
Why not simply have 2 A records pointing to the 2 WAN-IPs?
(but 2 MX records for 2 different hostnames should also work)

AFAICT this should work without problem
 
Would that work if I NAT 2 WAN IP to the same hostname?
It works with HTTP/HTTPS. When someone tries to load a webpage behind my firewall, and if WAN1 is DOWN then webpage loads thru WAN2. HTTP/HTTPS technology works with this kind of design

But VPN connections with same scenario do not work, If computer resolved FQDN for WAN1 IP it will try to connect to WAN1 VPN services, inspite the fact the WAN1 is DOWN. This happens because resolved Ip remain in computer DNS cache.

I thought MX would also would do same problem

Ok anyway
I will try
thanks you very much