I don't doubt Kerio's functionality (in fact I tested it out several years ago), but SME is not the proper platform for it. Instead, you should be looking at a minimal Centos LAMP installation as the base for Kerio. I don't see a Kerio on SME contrib getting much, if any, mainstream SME dev support because of the level at which it breaks/replaces core SME functions.
You seem to have misunderstood my reason for starting this thread. I have no long term interest in Kerio, it's simply an example of a better groupware application than Horde with at least as good email server functionality. My original question was: 'Can I disable the mailserver functionality of SME and replace it with Kerio, and if so, how?' For the area of business I operate in, the SME server is built in precisely the right way and can be operated without significant difficulty by folks like me, but Horde is now a glaringly defficient part of the 'core SME functions.'
Ed, I think you mis-understand my statements about SME's email functionality. Once again, most of what SME has to offer as a mail server isn't in its webmail app. SME is a very powerful mail server that lacks a good webmail frontend and some M$ exchange type functionality. There are quite a number of email filtering and spam prevention mechanisms under the hood with options that aren't available in the server-manager, but are available with console commands.
I am completely clear on what can be done with SME below the server-manager level - I use many of the mechanisms you refer to as a matter of routine, but they are not the point; none of them is superior to the built-in functionality of Kerio, or of Scalix, or of Zimbra. I have no arguments with the underlying email server in SME, my point is that Horde is simply unsuitable for the real world.
Groupware is an entirely separate discussion.
When I started this thread, Groupware was the *entire* substance of the discussion.

Given the pace at which online Groupware apps such as iGoogle are progressing , I think you'll see small to medium business moving away from expensive MS Exchange solutions to the very feature rich online services. My company, for example, uses iGoogle for our groupware solution with full push and shared email, calendar, addressbooks, and notes to mobile devices.
I wouldn't commit any of my clients to Google for a king's ransom - apart from anything else, the Google account pages are a day-dreamer's paradise. If we had a proper backend/client set for mail and calendars built into SME there would be no need to go near Google.
The best thing you can do is raise bugs in the tracker requesting the additional functionality.
Nope! I'm not seeking to divert SME from whatever path the developers choose to drive it down. I'm trying to find out how to disable some bits of SME and install a modern groupware server in their place. If this can be done, and if the resulting hybrid works, *then* is the time to write a feature request for consideration by the developers or by the programming members of the community.
Ed Form