I don't think there's a mail client program that will do it. It's quite possible to use a browser with perl/CGI on the server, platform independent.I have installed debian in our office - principally for use as a mail server, using courier-imap. We've got about 6 windows PCs and one debian box. Has worked without a hitch and everyone is very pleased with it. I'm wondering if it might be possible to convert our contacts database (currently we're using MS Outlook 2000) over to Openldap. There would need to be some simple way with which we could modify records in the ldap database. So far it looks as if you need to write a program that converts a .csv to an .ldif file then import it into ldap. This is much too complicated - we'd need to be able to use a windows client program to do that. So far I've got the impression that there is no easy way of doing this at the moment. Is there a website that explains how to do this?
I'm using thttpd, not apache, and three CGI scripts of about 3K each to do a simple listing (with Mailto: entries), an edit, and a new contact page. It's very crude and only has email names and full names. You'd want more fields for a proper contact list but that's not too hard. What it doesn't have at all is proper security (the ldap admin's password is hard-coded into the edit and write scripts) but that could be added. Ldap is good at permissions.
It's the perl LDAP module that does all the clever bits, and it wouldn't be hard to do a much more sophisticated job. The drawback is that you'd need to get a bit familiar with perl, which has a fairly sharp initial learning curve if you're used to more formal programming languages.
What you'll probably also find useful, if you don't already know about it, is LDAPExplorerTool which runs under Windows and allows you to see what's going on and fix mistakes.
-- Joe