i've been working on solving the one-long-line problem for Lou Proyect's marxism list. unfortunately, the fix requires a two line change to the Mailman source code. let me know if you are interested.
the problem is not just html-formatted posts. some email applications now allow the receiving end to handle formatting, and as a result emit paragraphs as one long line. in addition, Tahir's post came in plain-text but the content was quoted-printable as i recall. all this can be fixed easily with MHonarc archives, but Mailman uses its own archiver, and so requires the aforementioned small change.
Les