======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.7
- Linux/BSD distribution name and version:  Linux 4.2.6-1
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro? yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.

Hi Zhang,

We have 2 offices in different locations.
They share same email domain and served by 1 iredmail server.
Because of this the traffic between locations is high.

I want each sites have their own email storage.
Main Site  has their storage contain the local user mailbox.
Remote Site has their storage contain the local user mailbox.
So that the inter-office traffic can decrease.

But we also want to have simple user management via single LDAP server.

Presently when A of remote site try to send email with attachment to his colleagues sit beside him (we call it B) the mail will  goes to VPN to Main Site server, and B need to retrieve the mail also thru the VPN from the Main Site server. this traffics used the VPN bandwith

We like in the future that each sites have their own iredmail server, if local mail user of remote sites send email to colleagues of the own sites, the mail traffics no need to go thru the VPN and just work with the local mail server. Please review my images below.

Could we do that on iredmail?
How should we structure and config?