The company in our example uses the only domain called
company.com
. Supposing a company has its headquarters
in New York and a branch office in London. Kerio
MailServer is installed both at the headquarters and the branch
office (two separate licenses). The headquarters' server uses DNS name
mail.company.com
. The branch office's server uses DNS name
mail-ldn.company.com
.
We want the email transferred among local users in the branch office to be delivered locally, while the email addressed to users in the headquarters is really sent to the headquarters. The same thing should be guaranteed for the communication in the other direction — messages sent from the headquarters to the branch office must be delivered to the branch office's server.
Note: To keep the example as simple as possible,
suppose that users boss
and secretary
work in the headquarters and users technician
and
programmer
work in the branch office. The following
description is focused on these special requirements — it does not
include detailed configuration of the SMTP server, remote administration, etc.
Headquarters (configuration at the primary server
mail.company.com
)
In the company's headquarters (at the primary server
mail.company.com
) in Kerio
MailServer, set the company.com
domain as the
local primary domain.
In this domain, accounts of local users are defined (of those who work in the headquarters).
If Kerio MailServer is behind the
firewall, it is
necessary to make port 25
available for the SMTP service.
Create the ldn.company.com
domain where no
users and aliases will be defined. Set the Forwarding tab
under Domains in a way that email for the
ldn.company.com
domain is forwarded to the
mail-ldn.company.com
server of the branch office (see
figure 7.10 Forwarding settings).
Next, set aliases for all users at the branch office
(technician
and programmer
. These aliases
provide that email for corresponding users is delivered to domain
ldn.company.com
.
Branch office (configuration at the server
mail-ldn.company.com
)
Create a local primary domain company.com
with the alias ldn.company.com
.
In the local primary domain, create accounts for all users in this branch office (for those who will have local mailboxes at the other site).
Set that email addressed to the domain
company.com
is forwarded to the headquarters' server
mail.company.com
, while messages with the domain alias in
the recipient's address are not forwarded. This option guarantees that messages
where username or its alias is not specified correctly in the recipient's
address are caught.
Notes:
Set a secondary DNS MX record for the filial's server. This will help you avoid problems in case of the headquarters' primary server's failure.
The wildcard alias should not be used in branch office's server's, otherwise the email for the headquarters will not be forwarded.
If users want to access their email remotely (e.g. using
Kerio WebMail), they will always connect to the server
where their local accounts are created (i.e. users in the headquarters will
connect to mail.company.com
and users in the branch office
connect to the server mail-ldn.company.com
).
The Free/Busy calendar will display only information regarding local users of the particular server.