On May 12, 2016, at 04:16 PM, firstname.lastname@example.org wrote:
 Mime Digests & Summary Digests - I didn't see any difference for those two options.
There currently is no different between MIME and summary digests. We talked a long while ago about summary digests, but they've never been implemented. However, MM3 does implement RFC 1153 (i.e. "plaintext") and MIME digests and it should be possible to select your choice on your membership record, although I don't know whether this is plumbed through to Postorius.
The MIME format of MIME digests should roughly be:
multipart/mixed text/plain (the digest heading) text/plain (the TOC) message/rfc822 message-1 message/rfc822 message-2 ... text/plain (footer)