How to configure James and DNS Records for setting up 25 users each over 2 separate mail servers

[Arvind IK Chari <ar...@arvind.pro>]

Hi
I wish to have a multi server setup with Apache James Server where 25  
users each are set up on 2 different mail servers and all 25+25=50 users  
are on the same email domain.
As I am new to email, I only know how to setup a single server with all  
users of one domain on one server.
What DNS records do I have to configure and what setup for the James  
Server do I have to ensure (eg configuration/ storing emails etc) to make  
the above example setup work? Please pardon me if the question seems silly  
to you as I am a newbie to email server setup.

Yours sincerely,
Arvind.

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Re: How to configure James and DNS Records for setting up 25 users each over 2 separate mail servers

[cryptearth <cr...@cryptearth.de>]

Hello Arvind,

it's just a guess, but I don't think this will be possible, and if it 
is, it will be tricky.

DNS MX records only allow to a priority for all mail servers, but 
nothing about users.

For example: I have also two mail servers running: one on my root server 
wich is my main mail server, so it has a standard priority of 10, and a 
backup running on my home-network with a lower priority of 20. That way, 
I can ensure that complaint MTAs that respect priorities to always try 
my main server first, and only if it's unreachable or not responding 
(when it's down) fall-back to my backup. But: I have to keep both 
servers in sync (simple as I use database as storage and have database 
replication in place so local backup auto-sync from main root).

There were some additional DNS records specified in the original RFC 
883, but they never become widely used, only MX survived (even SPF felt 
back to TXT). So even DNS technically was designed with such "issues" in 
mind, it never became widely adopted.

TLDR: if you want to have different users under one domain you need to 
have a central user-database each mail-server can access. If you want to 
split users in groups maybe consider sub-domains. I don't see how this 
would be possible with james or any other modern mail-server without 
tinkering some self-made back-end. Even Google have to have some sort of 
central user-database(-network) each of thier mail-servers can access. 
There is no way that one mail-server would say: oh yes, I have this user 
- and others for the same domain: nope, don't know this one. When MX 
priorities it's up to the MTA how to choose from multiple servers.

Matt

Am 20.06.2019 um 11:56 schrieb Arvind IK Chari:
> Hi
> I wish to have a multi server setup with Apache James Server where 25 
> users each are set up on 2 different mail servers and all 25+25=50 
> users are on the same email domain.
> As I am new to email, I only know how to setup a single server with 
> all users of one domain on one server.
> What DNS records do I have to configure and what setup for the James 
> Server do I have to ensure (eg configuration/ storing emails etc) to 
> make the above example setup work? Please pardon me if the question 
> seems silly to you as I am a newbie to email server setup.
>
> Yours sincerely,
> Arvind.
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: server-user-unsubscribe@james.apache.org
> For additional commands, e-mail: server-user-help@james.apache.org
>


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