You could use QoS type services to limit email network bandwidth used by only
one server by all locations, but this might reduce the apparent speed of the
connection to your users. With one server, people can't use email if their
connection drops. What type of WAN links do you have? Can you use cheap
high-speed access an use VPN between the offices to use only one mail server?
If bandwidth is a major concern, IMail peering with 4 servers might be an
issue. If bandwidth is an issue, and you decide on multiple servers, one way
to do it is with a meta-like mail domain which contains aliases to the real
addresses on the corresponding branch's mail server. Just create aliases
where the destination would simply contain [EMAIL PROTECTED] All
outbound email from all your other servers would go through the meta-server as
a relay host (could be a separate server at HQ, or a virtual domain on the
existing HQ server).
Each mail server's mail domain would be configured as <branch>.yourdomain.com.
By default your users' reply to fields would contain the branch where they are
located at. If you want the email they send to reflect just "yourdomain.com",
you could change their reply-to address to be the correct
"<user>@yourdomain.com".
[Server1]:
DOMAIN: yourdomain.com (virtual meta-domain)
alias: user1 >> [EMAIL PROTECTED]
alias: user2 >> [EMAIL PROTECTED]
...
alias: user12 >> [EMAIL PROTECTED]
alias: user13 >> [EMAIL PROTECTED]
DOMAIN: boston.yourdomain.com
user1, user2, user3, ...
[Server2]:
DOMAIN: toronto.yourdomain.com
user12, user13, user14 ...
[Server3]:
DOMAIN: chicago.yourdomain.com
user23, user24, user25, ...
This does increase admin burden, on the virtual meta-domain, but for such a
small group of users it's not that big a deal. The problem is that you'd need
a mail server for each branch (costly for so few users).
-ives
----- Original Message -----
From: "Dan Star" <[EMAIL PROTECTED]>
To: "iMail List" <[EMAIL PROTECTED]>
Sent: Thursday, June 12, 2003 10:23 AM
Subject: [IMail Forum] Distributed Mail Servers?
> Hi,
>
> I am wondering if distributed mail servers are possible on a private
> network with iMail. We have 4 branch offices (20, 10, 10, 10 persons
> respectively) and one HQ with HQ having the mail server. We sometimes
> get the WAN pipes filled with POP3 pull traffics and client SMTP push
> traffic. One idea to solve this would be to have local mail servers at
> each branch on the private network (192.168.X.X) for branch local
> traffic and have the "public" email server route incoming mail to the
> right internal server. I realize that this increases admin burden. I
> am interested in and comments. I am also considering traffic shaping
> with a device like packeteer.
>
> Regards,
> Dan
>
>
> To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
> List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
> Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
>
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html
List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
