1:45AM ET -- Heard back from the support people. They created a new list, on the same server as ours, using the the same settings -- and they were unable to replicate our problem. Below is the message they sent me verbatim: ================================== Hi Evan, After running the test list on the server you are on, I've set the following on your list - so that it matches what we used on the test list. ****************** Content filtering: Should Mailman collapse multipart/alternative to its first part content? (Edit collapse_alternatives) YES Should Mailman convert text/html parts to plain text? This conversion happens after MIME attachments have been stripped. (Edit convert_html_to_plaintext) NO ***************** We tested sending HTML emails and plain text emails, and used several email programs to check reception. In every case, the subject and message body is showing as correct. In short, we haven't been able to replicate the issue as described. Mail sending and reception tested on: Thunderbird Alpine SquirrelMail Roundcube Gmail.com Yahoo.com AOL.com There is nothing in the log files reporting errors on your list. So at this point we are none the wiser as to why this is only happening for users on your list. A last ditch effort would be to remove your list completely, and create a new one. This would just be voodoo if it made any difference at all - as there is nothing logical about why that would make a difference. Before we do that though, you may want to try one last message to the list to test the change I made. I suspect all your members are getting fed up with test messages.