I’ve been experimenting with Mac versions on my own server, with varying levels of success. The native Mac versions, or at least some of them, seem to work fine connecting to an unofficial server. They should behave more or less like the Windows versions, although it depends which version of MacOS you’re running.
Here’s the info I have for Mac versions:
Version: 1.0r065
Protocol: MSNP3?
CVR: macmsgs/macmsgs?
MacOS version: 9.2.x?
Version: 2.5.1 (About dialog says 2.5.0, but client reports 2.5.1 when connecting)
Protocol: MSNP5/6
CVR: macmsgs/macmsgs
MacOS version: 9.2.x?
Version 2.0r37
Protocol: MSNP5/6
CVR: macmsgs/macmsgs
MacOS version: 10.2.0+?
Version 2.0r44
Protocol: MSNP5/6
CVR: macmsgs/macmsgs
MacOS version: 10.2.0+?
Version: 2.1.0
Protocol: MSNP5/6
CVR: macmsgs/macmsgs
MacOS version: 10.2.0+?
Version: 3.0.0
Protocol: MSNP5/6/7
CVR: macmsgs/macmsgs
MacOS version: 10.1.0+
Version: 3.5.1
Protocol: MSNP8
CVR: macmsgs/macmsgs
MacOS version: 10.2.0+?
Version: 4.0.1
Protocol: MSNP8
CVR: macmsgs/macmsgs
MacOS version: 10.2.0+?
Version: 5.1.1
Protocol: MSNP9
CVR: macmsgs/macmsgs
MacOS version: 10.3.0+?
Version 6.0.3
Protocol: MSNP13/14
CVR: macmsgs/macmsgs
MacOS version: 10.3.0+?
Version: 7.0.1
Protocol: MSNP13/14
CVR: macmsgs/macmsgs
MacOS version: 10.4.0+?
Version: 7.0.2
Protocol: MSNP13/14
CVR: macmsgs/macmsgs
MacOS version: 10.4.0+?
Version: 7.0.3
Protocol: MSNP13/14
CVR: macmsgs/macmsgs
MacOS version: 10.4.0+?
Version: 8.0.0
Protocol: Probably MSNP16?
CVR: Probably macmsgs/macmsgs like all the others?
MacOS version: 10.5.0+?
Version: 8.0.1
Protocol: MSNP16 (thanks @TReKiE)
CVR: Probably macmsgs/macmsgs like all the others?
MacOS version: 10.5.0+?
Version: 8.0.2 - Final version, recommends upgrading to Skype
Protocol: Probably MSNP16?
CVR: Probably macmsgs/macmsgs like all the others?
MacOS version: 10.5.0+?
So basically 6.0.x and above are incompatible with Escargot (because they use newer protocols), Messenger for Mac 5.x might work, I haven’t tested them with Escargot. That only leaves you with very old (and PPC-only) versions, so unless you have an old PowerPC-based Mac with either MacOS 9.2 or MacOS X 10.2 or higher, I guess you’re out of luck for the moment. Running Messenger for Mac 5.x under Rosetta on Leopard might work, but I haven’t tested that, as I don’t have an Intel Mac to try it on.
With my own server I’ve been able to get a number of these native Mac clients working, using host files and manually installing SSH certificates, and they don’t seem to be substantially different to the Windows versions as far as the server is concerned. If you do have a machine that can still run these old clients, and if you’re lucky, it might be possible to connect them up to Escargot with a little bit of tweaking.