I never said IMAP == Exchange...

I'm all for a healthy debate on the relative merits of proprietary solutions over those based on open standards, and that seems to be where we are with the recent discussions on Exchange and open source equivalents.

Alex has responded to my post about the comparative merits of Exchange and open source solutions.

It seems however that some of my comments have been mis-read or mis-understood.

I originally responded to Alex's request for an open source email solution that allowed secure message and 'smart client' functionality in the same way as that provided by XML over HTTP, which is what Microsoft's Outlook and Exchange use.

As part of that solution I recommended IMAP. IMAP is the mail access protocol that enables us to read and store messages. Unlike POP3, IMAP provides full-server side storage and public folders which provides all of the functionality offered by the email component of Exchange.

IMAP is not - and I never claimed it was otherwise - a complete solution for all the functionality offered by Exchange. In fact, I pointed out that many of the open standard protocols out there provide the rest of the various gaps, and all of them support SSL connections. For example, want a global address book? Use an LDAP server (which is what the core of the Windows Active Directory provides, it even exposes itself as LDAP if you want it to).

If you want the other functionality offered by exchange (as pointed to by Alex and those handy, Microsoft, websites) then use these other protocols and standards.

By the way, it amazes me that Microsoft are willing to get away with comparing the functionality of a full email and collaboration system (Exchange) by comparing it to a mail access protocol as if they are equals.

Since IMAP and POP3 are components for accessing email within Exchange, you'd think Microsoft would be smarter than to compare the entire Exchange offering with just a portion of Exchange's own internal feature set.

This is a bit like a supermarket comparing the entire range of food they offer with their own fruit and vegetable department and declaring the entire supermarket as better. Well, Duh!!

IMAP is not, never has been, and never will be, a replacement for an Exchange. It is, however, an open protocol for the reading and filing of email.

Now to some of Alex's other points:

This article on CommunigatePro was written in 2003. True, it points out that CGPro's web interface wasn't as good. In 2003 I'd be inclined to agree. But then two years is a long time in the computer software world and hardly indicative of their current offering.

While I'm at it, I should point out that CGPro's Web interface - and many others in the open source world - are completely customizable. If you don't like CGPro's interface but still want web access as well as Outlook support then you could change it. Alternative, you could try one of the other solutions, like Scalix.

I've seen mail solutions that emulate the look and feel of Outlook - not, as far as I'm concerned, the nirvana of interfaces - and I've seen others that are much better. I've even seen some solutions that are tailored very finely to the way an organization works, without ever losing the core functionality, therefore helping Staff concentrate on what matters, rather than what looks good.

Back to the main thread...

Alex is right that Outlook and Exchange provide a complete collaboration system. He's wrong to suggest that equivalents don't exist in the open source and Linux community. CommunigatePro, Scalix and others all provide the same functionality as Exchange - that's why they exist. Want shared calendars, meeting facilities, the Global Address Book etc? They all exist in these ready to run Linux offerings, and they are all compatible with Outlook as well as non-Outlook alternatives such as Thunderbird or Sunbird.

Want Blackberry and push technology? Check out the Scalix offering which provides push technology for Blackberry and other devices.

Open-Exchange is a good product, and in fact offers slightly more than Exchange does, including document management and project management functionality integrated into the rest of the system (getting Microsoft Project Server to integrate effectively can be a pain, although I think the latest version is a vast improvement).

If you enable IMAP support on your Exchange server then Apple's standard tools (Mail, Address Book, etc) can access most of the functionality of Exchange. If you want the full works, then as Alex suggests use Entourage. Entourage has a few bugs (I haven't used it in centuries because the bugs were worse than the benefits).

Linux client support for Exchange is bit of an unlikely situation, but if it's really important to you then use Ximian Evolution which can connect to Exchange and indeed any of the open source, open standard solutions out there. Of course, if all you want is email and LDAP access then there are very few tools in the open source stable that don't support IMAP and LDAP.

Incidentally, much of the functionality provided by Exchange can also be provided directly by OS X Server. While it is an Apple product, OS X Server is built entirely on open source software and includes OpenLDAP (for directory/address book), Cyrus (for POP/IMAP), Postfix (for MTA), Apache and WebDAV (for calender functionality), group chat (through the built-in iChat client and server). OS X server also provides Active Directory authentication support (for your Windows clients), supports Outlook for much of the functionality and supports nearly all the protocols mentioned above over a secure connection (iChat excepted, AFAIK).

And it does it *all* using open source packages and tools, all of which in turn are based on open protocols and standards. By definition, that also means it supports just about any platform as a client that you want.

As I said at the start, I like a healthy debate. Alex's original challenge was a smart client, secure (without VPN) email/collaboration system that doesn't use Exchange. He extended that in this last post to include some other functionality to, such as support for Blackberry's and push technology.

The open source solutions I've suggested support everything Alex wants, and they do it using open standards and open protocols, and they all offer secure options for the exchange of information.

To suggest that these products cannot compete head-on with Exchange is ludicrous, especially since the very reason that these products exist is to compete directly with Exchange on it's features and functionality.

I'm not trying to suggest that these products are better than Exchange, and I certainly don't think that these solutions will be right for everybody, but I do think they offer a perfectly reasonable and valid choice and alternative to Microsoft solutions and often they do it using open standards that automatically make them more compatible and flexible. And yes, while it isn't a main part of my argument, often they are cheaper too.

One area where Alex and I do agree is on how to make your choice. I cannot add anything to what Alex has said - you need to determine what you want to do, what you and your staff know and want to work and support and you need to be sure that the solution you choose is right for you.

I'm happy with my open source, open protocol, secure, Outlook, Apple Mail and just about any other client I choose, friendly solution. And so are my clients. That is all that matters to me.