Company with one email domain and multiple offices
Information and Requirements
-
A company has three offices in geographically separate locations (Prague, London, and Paris) and would like to use the same domain name (company.com) for all email.
-
The company would like to manage three separate KMS MailServers to optimize the speed of email browsing and maintain unique policies for each location (e.g. Linux PAM in Prague and Active Directory in London and Paris).
-
For simplification purposes we will assume there is only one user at each location (Tomas in Prague, Pierre in Paris and Henry in London).
-
The following aliases will apply: support@company.com should be received by Pierre, sales@company.com should be received by Henry and info@company.com should be received by Tomas.
-
Only one mail server is able to receive email (from the Internet) to the domain (company.com), however email must be properly forwarded to the mail server of the other offices, even though they are within the same domain (company.com).
Implementation
Headquarter
-
In each Kerio MailServer define company.com as the Local (primary) domain and add the users to each respective location (e.g. Tomas in the Prague server, Pierre in the Paris server and Henry in the UK server).
-
In order for email to be forwarded from one KMS to another, while still using the same email domain (company.com), special subdomains must be created to allow for internal routing of email between each location. The following subdomains would apply to this example: uk.company.com, cz.company.com, and fr.company.com.
-
On the mail server located in Prague, a forward domain (fr.company.com) should be added and configured to forward to the IP address/hostname of the mail server located in Paris. The alias support should be added to the Local domain (company.com) and should deliver to the email address support@fr.company.com so that email sent from the Prague office will be properly routed to Paris. Another forward domain (uk.company.com) should be added and configured to forward to the IP address/hostname of the mail server in London. Add an alias for sales in the Local domain (company.com) with a deliver to address of sales@uk.company.com.
-
Create the fr.company.com domain where no aliases nor users will be included.
-
Use the Forwarding tab in the Domains section to ensure that mail for the fr.company.com domain will be forwarded to the server of mail-fr.company.com.
Figure 1. Forwarding -
Set aliases for all users included in the particular location (Domain Settings Aliases), in our case the support and sales users. These aliases define that mail for the appropriate users will be delivered locally to mail-fr.company.com. Mail for other users will be sent to mail.company.com.
Figure 2. Defining Alias
Office
-
Create a local domain company.com, that will use the fr.company.com alias.
-
In local domain create accounts for all users of this office (for all that will have their own local accounts in the office).
-
Define that all mail for the company.com domain will be forwarded to the server of mail-office.company.com. Set that messages that include the domain alias in the recipient's address will not be forwarded. Using this option you can capture messages that do not include correct username or his/her alias in the recipient's address.
Figure 3. Prevent loops in distributed domain scenarios -
If users intend to access their mailboxes remotely (i.e. using the Kerio WebMail interface), they will always connect to the server where their local accounts are located (users connecting from the headquarters will connect to the mail.company.com server and users connecting from the office will connect to the mail-office.company.com server).
