Jerry if they don't use Paperless emailing, I don't believe SSL could be involved in any other way. Ah except for credit card processing (Paya/SPS, APS, etc), Payroll Tax Calc in 2018 (to the SPA web service) and probably the other connections you see in Library Master / Setup / URL Maintenance.
Also, I'm thinking ChilkatMail DLL uses some standard way of specifying SSL/TLS and that is the SMTP Server (e.g. Exchange Server, Google Mail, etc) that listens on a port designated for SSL/TLS.
You could also point out to them their current version of Standard doesn't use SSL (obviously) and neither will 2018 Standard and since that concern is arising because Sage 100 is being placed on the same VM as the other division's ERP, it is allayed by simply putting Sage 100 on it's own VM :)