Sending email with TLS (via Outlook) from LC 6.7 based app...

[Ben Rubinstein]

A very venerable app (original version perhaps 15 years ago) is still running 
on a client's Windows box, every night, processing data and emailing a report.

The email is sent using Shao Sean's libSMTP library, which has performed 
faithfully for all these years. Unfortunately, the client's replacing their 
local smtp server with outlook365.com - which requires TLS authentication - 
which I don't believe libSMTP supports.

The current version of the app is built in LiveCode 6.7.11. There is a huge 
amount of text to be processed, and - as you might imagine after this long 
development, with regular changes and additions - the processing is very 
complex. A few years ago I did look at rebuilding it in LC 8/9, but because of 
the changes to unicode handling there was a lot of perturbation in the data, 
and there wasn't time/budget to track all this down in order to get a 
reasonable new version. I still occasionally need to make tweaks to the 
processing, but I do that in my trusty LC 6.7.11.

So now I've hit a problem. There still isn't budget for a major exercise to 
rebuild it in a modern version of LiveCode, so I can't just switch to using tsNet.

Is it theoretically possibly to tweak libSMTP to work with TLS, or is there 
some basic limitation with LC 6.7 that would make that impossible? Are there 
any other libraries that work with TLS? Or (I'm not a Windows person) is there 
some simple way I could set up a local SMTP server on the Windows box that 
would accept the email from my LiveCode app and forward it to outlook365?

Any suggestions or experience gratefully received.

Ben