What we have: extremely cheap dedicated server with configured corp mail server. Unreliable work plus it has permanent troubles with mails verifying (configured by another person).

What we need: at least several important addresses with 99% reliability.

Idea how to reach that: Pay to mail provider (right now i'm thinking about G Suite) for several high-reliable addresses, leaving every other user on dedicated server.

So, what we must get at the end - two MX servers, same mail domain, each server handles it's own addresses. I'm hardware engineer, so that part of configuring is totally unclear for me - is it possible to make such configuration? I know that it's possible to add second MX server with same address list for redundancy, but what about my variant? Is it even possible somehow to make routing inbound mails between different servers? (as i understood outbound mails won't be a problem at all).

For saving your time - i know that normal reconfiguration of dedicated server or full migration to G Suite is much more easier, but sadly both options aren't for me :(

Also question for G Suite experienced users - is it possible to setup some sort of mail relaying in G Suite? For example, i'm placing 1 MX record with google MX server in domain. If letter arrives at a@domain.com - it goes into G suite address, and if it's b@domain.com - google MX relays it to another server.com. I'm not so good in MX technology, so maybe my question is dumb :) But such solution will also work well in my case.

  • @JennyD thank you for the suggestion, but it isn't. For now i'm looking for the solution on my own so if i'll succeed faster than our community i'll post the answer how to do it :)
    – Looongcat
    Jul 11, 2017 at 8:02
  • Possible solution was mentioned in serverfault.com/questions/827757/… , i will try that way
    – Looongcat
    Jul 11, 2017 at 8:07

1 Answer 1


So, answering my own question.

In G Suite such feature can be easily done with "G Suite routing". How to turn it on:

  1. Modify DNS records for primary MX server (G Suite in my case)
  2. Create new additional host in "Apps - Gmail - Advanced - Hosts"
  3. Add new route in "Apps - Gmail - Advanced - Default routing" with selected "route" option and "apply only to unknown addresses"

Such solution will have only one "not good" feature - if you're mailing with some person which has mail address on untrusted server - google's spam filter will reject his mails. It can be fixed with turning off spam filter in route settings.

Also you should be aware to use TLS for mail relaying (setting is in "Hosts"). If you don't know any reason to use TLS - don't manage mail server :)

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