I was unaware that Threads in any version ever let you reply to a post from a subscription email. I have had Threads since version 5.5 and this was never a feature of Threads. Knowing the checks that have to be done to do something like this I doubt it ever was a feature.
This question has been asked before and there is no hack that allows a reply to a post via email. JoshPet seems to remember a hack for the perl version. Here is a link to the thread.
https://ubbdev.com/forum/showfl...ew=collapsed&sb=5&o=&fpart=1
