Haiku SMTP troubleshooting

I cannot seem to get Haiku Helper successfully talking to an MS Exchange SMTP server. TLS is enabled, have tried different authentication mechanisms, ports 25 (with basic authentication set to occur after TLS is established) and 587 with no joy; is there a way of seeing the SMTP conversation from the Haiku end? The only thing I see in the console log is 'communications error: could not send e-mail message: 1:A stable connection to the server could not be established. 
 
Here is the log from the Exchange end (also tried disabling tarpit on the Exchange box- didn't help):
 
2015-02-05T10:28:05.528Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,21,192.168.0.253:25,192.168.0.252:49630,*,Tarpit for '0.00:00:00.390' due to 'DelayedAck',Delivered
2015-02-05T10:28:05.528Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,22,192.168.0.253:25,192.168.0.252:49630,>,250 2.6.0 <d2062f6e-eb02-4a26-ad64-92f26891332f@WIN-GKLPNUTRF8T> [InternalId=6900] Queued mail for delivery,
2015-02-05T10:32:11.781Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,23,192.168.0.253:25,192.168.0.252:49630,<,,
2015-02-05T10:32:11.781Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,24,192.168.0.253:25,192.168.0.252:49630,*,Tarpit for '0.00:00:05',
2015-02-05T10:32:16.796Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,25,192.168.0.253:25,192.168.0.252:49630,>,500 5.3.3 Unrecognized command,
2015-02-05T10:32:16.796Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,26,192.168.0.253:25,192.168.0.252:49630,<,quit,
2015-02-05T10:32:16.796Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,27,192.168.0.253:25,192.168.0.252:49630,>,221 2.0.0 Service closing transmission channel,
2015-02-05T10:32:16.796Z,WIN-GKL\minimac receiver,08D1FDADF49BC360,28,192.168.0.253:25,192.168.0.252:49630,-,,Local

Its possible this mail server isn't compatible. Gmail works great though, so that might be an option?

can you advise what the SMTP commands are that Space issues? Is there a flag to allow non-TLS?

The default port is 465. TLS is required and cannot be turned off.

The port can be overridden by adding a : after the SMTP server address. I don't have the exact commands issued unfortunately, as we are using a library and it may depend on the server/etc. We have heard of MS Exchange not working in the past. The simplest solution is to use Gmail.