Is there a way to make the subject line more clear about which is the first message in a new thread and which are replies? That old fashioned “Re:” is tremendously useful.
Yes, we can have Re: prepending replies, and I’ve applied that change in the settings.
I don’t know what you did, but threading worked in this and the “pushing OS updates” after 8am!
New Topic should default to "TidBITS Talk"
I added Re: to replies, so that should help older mail clients figure out threading better. @cwilcox, see if it makes a difference for you.
Threading in Apple Mail
Thanks, yes, the addition of "Re: " to replies seems have made Sierra Apple Mail happy. Messages in “Sending email into Discourse” and “Apple pushing OS updates” are properly threaded. Curiously, “Discourse subject line” and “New Topic should default to ‘TidBITS Talk’” are threaded together. Maybe the latter was spun off the former and this is just a by-product of the timing of some message before before and others after the addition of “Re: .”
Yes, I did something there (can’t quite remember what) to keep the threads on topic. There must be some message-id magic going on in the email threading too.