While the current implementation of Thread-Index looks like working (see MDL-52997), it should be evaluated in a more friendly way as per Microsoft specs: see the detail here.
- has been marked as being related by
-
MDLSITE-4457 Missing "Re: " in forum email notification
- Closed
- is a regression caused by
-
MDL-52997 Forums emails not threading correctly for deeply nested forums
- Closed