Digest delivery in mailman 2 encapsulated the individual message/rfc822 messages in a multipart/digest container. This allowed email clients to show the messages in the particular digest in a threaded view.
It seems like the various digest options that I have tried [1] in mailman 3.1.0 (as implemented for the fedora-users mailing list) no longer encapsulate messages in multipart/digest.
Is this intentional? Is it a bug - feature that was lost in translation from 2 to 3? Is there a delivery option I'm missing that will turn that back on?
[1] Mime Digests & Summary Digests - I didn't see any difference for those two options.
Here is a sample of mime types that I used to get with mime digest delivery in mailman 2 (notice the multipart/digest):
Content-Type: multipart/mixed; boundary="===============1472225091712365472==" Content-Type: text/plain; charset="utf-8" Content-Type: text/plain; charset="utf-8" Content-Type: multipart/digest; boundary="===============6619260109017411105==" Content-Type: message/rfc822 Content-Type: text/plain; charset=US-ASCII Content-Type: message/rfc822 Content-Type: text/plain; charset="UTF-8" Content-Type: message/rfc822 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Type: message/rfc822 Content-Type: multipart/alternative; boundary=001a11c3cab0b7b2d5052f6fcd1e Content-Type: text/plain; charset=UTF-8 Content-Type: text/html; charset=UTF-8 Content-Type: message/rfc822 Content-Type: text/plain; charset=UTF-8 . . Content-Type: text/plain; charset="utf-8"