"unencrypted communications" relates to the user's end. This could be any one of your members or yourself, if you were to log in using a free or untrusted wifi connection (think; hotel or starbucks or mcdonalds or anything open in the wild).
the bulk of that message is scare tactics fud. i would receive similar spam emails many years ago by companies offering to convert my website for a small fee. even though I had already been on https for several years prior. but overall, you really should already be on https by now. you have user logins. you are not sending static html source. each of your forum pages is presented per each of its account access levels.
A simple guide has already been put together to help you move your UBB.threads forums from basic http to https:
https://www.ubbcentral.com/forums/u...transition-your-forum-from-http-to-https
