I am subscribed to two of my own digests on different LISTSERV hosts
(which are at different organizations) which are at the same RELEASE
level and appear to be on UNIX hosts.  Both Subscription options are
identical (MIME DIGEST), yet my droid client does NOT handle the text
attachments of the one host whereas it does OK with the other.  Using my
laptop client (Thunderbird), I do not have difficulties with either.  A
close inspection does show a different in the generated heads (something
about RFC822).

Just FYI