Hi Paul,
You're probably gonna get lucky Paul, but take this as a warning because I predict pretty soon you're gonna have a problem.
The root of the issue is that the internet is a very fluid beast. So things are changing all the time with regard to what services support, and don't support. Many services switched to SSL, then to TLS and then potentially to TLS 1.1, 1.2 and so on.
Last November an issue with SSL v3 surfaced which has resulted in many services turning off support for SSL v3. More recently there has been a push away from TLS 1.0 to TLS 1.2 and I expect that in future months and years that will continue.
NetTalk 6 supports SSL up to TLS v1, but not 1.1 or 1.2. Obviously later NetTalks have that support, but you're in Clarion 5.5 so your update path there is limited.
So here's the short answer - You can fully expect Clarion 5.5 programs to slowly start not being able to connect to any external services. That includes mail, ftp, web, whatever. Most everything is moving to secure now (email used to be plain-text but is now often SSL, same for FTP and same for Web.) You probably have a window to update the program, or alternatively for the parties to accept that it will gradually degrade in abilities.
Regarding the Hotmail settings - I would recommend using the NetDemo program and playing with the different settings it offers to determine what the best combination for hotmail is. If you're lucky they haven't discarded TLS 1.0 completely yet.
Also test with the NetDemo from your NT8 or NT7 - that will be the best test, then you can try back porting those settings to the 5.5 app.
Cheers
Bruce