Exchange 2003 vs. Sendmail Mail Routing?

good soldier svejk asks: "I am a unix sysadmin at a medium sized (~10,000 user) organization. We currently using Exchange 5.5 for messaging, calendaring etc., and sendmail for mail routing and relaying. We arrived at this architecture because Exchange 5.5 was neither flexible enough to route our mail nor secure enough to meet our relay control standards (my Windows counterparts tell me it has since improved it's relay control). Now we are looking to upgrade to Exchange 2003 and the boss wants to know if we can eliminate the sendmail layer. We use LDAP mail routing across multiple domains and Brightmail Anti-Spam. We have not yet implemented Active Directory. Does Exchange 2003 offer a sendmail comparable level of configurability and flexability regarding routing, access control, filtering, virtual hosting and queue management? Just as important, is the Windows 2000/Exchange 2003-SMTP combination adequately securable for use in the DMZ?"

Comments

Better get Active Directory setup...

[questionlp]

If you want to upgrade to Exchange 2003, then you will need to get Active Directory setup, prepared and configured as stated in the Exchange 2003 documentation :)

You have a major problem.

[Talonius]

Exchange 2003 requires Active Directory, quite an undertaking in an organization of your size.

I would investigate the repercussions of that requirement before moving forward with any other research or comparisons.

Lots of work...

[seigniory]

I'm in the same predicament here. We're a small company (~500) but handle more email than most 10,000 shops - mostly customer service-related mails.

Anyway, first off, I'd like to say that if you have a 10,000 person organization, and you'renot running AD yet, handle that first. I'd guess that you're looking at at *least* 4 months for planning and implementation of your AD environment.

Also, you might as well go right to Windows 2003 (AD 2.0) since Exchange 2003 can only run in an AD 2.0 environment and on Windows 2003 server.

Finally, yes, Exchange 2003 routing is much better than 5.5 (which was hooooriiiible). Now, if you're familiar with sendmail routing, who cares? :-) The only way you're going to be able to do the Exchange 2k3 (or 2k) routing you require is to program some custom COM event sinks in a .NET language.

If you question is "can it be done" the answer is "sure it can". Just remember that just like any major infrastructure change, it ain't gonna be easy or quick to do.

Luckily, we were able to upgrade to Exchange 2k3 with little trouble. I'm still trying to get the hang of the custom event sinks, but it's coming along. I'm a perl guy and trying my best to use Perl.NET but there's few resources out there to help out with the nook I've created for myself.

If you're looking for spam/anti-virus management - definitely check out Postini (www.postini.com) - they rock and are pretty cheap ($1.25/month/user). Setting us up with this service removed 4 front-end mail relays from my DMZ and dropped our spam over 90%.

That's my $0.02.

And for those looking for alternative systems...

[rainer_d]

Exchange does more than just email, so you can't replace it with a qmail-toaster.

SamsungContact
SuSE Openexchange Server
Oracle Collaboration Suite
and
Lotus Notes

are viable products that don't rely on AD and MSFT-products.

I use qmail for myself, but it's not something for people who need calendaring.
Disclaimer: my company re-sells SuSE's product.