[PLUG] Mail Network Options

[Geoff Burling]

On Thu, 27 Feb 2003, Keith Nasman wrote:

> A client of mine is putting in another office location and I am to put in
> a server there. Right now they only have one office (we'll call it
> office1) with a fixed IP and their mail and website are on the
> server(server1) there. I will be installing server2 in office2 on it's own
> fixed-IP DSL line. I'm exploring the different options for delivering mail
> from server1 to server2.

It sounds like you have half of the problem solved. Let me repsond to each
point as they come up.
>
> 1) First thought was to just put .forward for each user to send the mail
> to user at new.ip and setup postfix to accept mail to the IP. For office2 to
> add a new user, they would have to add the user into server1, add a
> ..forward, and add the user to server2. Of course, if server1 is
> inaccessible office2 doesn't get their mail.

Well, you could do something like this, especially if you are dealing with
a small business of less than a dozen people total.
>
> 2) Don't do the .forward routine and just have all mail that doesn't have
> a user on server1 forwarded to the server2 and then bounced if there is no
> user. This is easier maintenance-wise but has the same fault of server1
> going down.

I don't think this is the best solution, even though it handles the
spam problem.
>
> 3) Set up the upstream DNS MX records to point server1.domain.com to one
> IP and server2.domain.com to the other IP. This avoids the server1 link
> problem. My question is whether or not the users could still have
> user at domain.com addresses at the office2 location or would they have to
> have user at server2.domain.com as their addresses. I'm guessing that they
> would have to be user at server2.domain.com.

As I understand standard practice -- & assuming that your client isn't
about to allow workers at one site to commute to the other -- this is
the way many commercial domains with multiple sites are set up. By this
I mean that setting up proper MX records with one server acting as the
secondary for the other is a Good Idea. Then IT takes the next step &
aliases all of the mailservers under one domain, so that to the outside
world everyone has an address in the user at domain.com form.

The other way this is done is to have one machine set up as a central
mail server, but still do the aliasing. Then the two offices use SMTP &
POP3 to send & receive email, & with the right kind of magic, your client's
employees can read their email from either office. The trick lies with
the aliasing, which I kinda remember how to do with sendmail -- but unless
you want to learn sendmail, I'd advise you to stick with either postfix or
exim.
>
> This is my first dealing with multiple physical locations under the same
> domain so I'd like to get more input on how this is normally done and
> whether there are other (probably obvious) options out there that I need
> to look at.
>
Well, I know the theory of this quite well: I haven't done the actual
implimentation, so I for one would like to hear how you solved this
problem & about any gotchas you encountered.

Geoff