MS Exchange server on FreeBSD?

[Anthony Atkielski]

Jim Durham writes:

> Personally, I wouldn't wish Exchange on my worst enemy. It uses a
> database to store mail and, if that database becomes corrupted, 
> you can lose all the email for the company.

All e-mail systems use a database of some type; the only differences are
in how visible the structure of the database is to the outside world.

Exchange uses a custom variation of the database manager used by Access,
called (if things haven't changed recently) Jet Blue.  It was chosen
because it was compact and performant and placed relatively few
restrictions on the format of the data stored within it.

If the database becomes corrupted, which is highly unlikely, you must
restore it from your last backup (every mail administrator takes
frequent backups, which can be done online with Exchange).  One
advantage of Exchange is that only the Exchange Server accesses the
database; everyone else communicates with the server, but does not
access the database directly.  Since many cases of database corruption
arise when independent processes access a single database, this
eliminates an important point of failure.

> This will make you extremely unpopular. We had it happen once and just
> moved everyone over to Sendmail and never lost an email for 5 years
> now.

Clearly, your organization had no need for any of the advanced features
Exchanges provides.  In some companies, a move from Exchange to sendmail
would engender the creation of lynch mobs.  Users tend to become very
attached to Exchange features.

I've seen Exchange servers run for years without any instance of
database corruption, and it's not a serious problem.

> It also has no concept of how internet mail works. It
> creates an environment where, if you are not running Outlook, 
> you are "outside the loop". It is its own world and not really 
> internet mail as we know it.

Proprietary systems always work that way.  Exchange works that way
because virtually all the features it provides are unknown to the
relatively simple Internet e-mail standards.  It _has_ to do it in a
proprietary way, because there isn't any standard way.  There are no
RFCs explaining how to share calendar information across an e-mail
network.

Nevertheless, Exchange does communicate with other MTAs without any
trouble using standard Internet protocols.

> Also, you have to run it on  a Windows "server". which is not a
> server at all, but a glorified 2000 box or XP box.

Actually, you have it backwards.  Windows-NT based boxes on the desktop
are actually scaled-down servers.  NT and its successors (200x and XP)
were designed primarily as server operating systems.

Exchange is tightly integrated into the Windows server architecture and
runs very well with it.  However, it's also true that it won't run on
anything else.  It's best to have Windows servers dedicated to Exchange
(if the organization is so small that it can get by with Exchange
running on a more general-purpose machine, it's probably too small to
profit from Exchange).

> Anything that wants you to kick off all the users just because you
> installed a new piece of software is a toy server. You don't want to
> deal with that in a 24/7 world. There's never a time you can do that
> unless you *like* coming in Sunday night at midnight!

You don't install things on a dedicated mail server.  Once it's up and
running, it stays unchanged for years at a time.

-- 
Anthony