On 06/09/2014 01:27 PM, Timo Sirainen wrote:
Another thing I'm wondering about is if I should allow text/html parts, because removing them will also break the DKIM signatures. Or mainly I'd like to allow only multipart/alternative with text/plain + text/html, but I don't think I can configure Mailman to support that.
Yes you can, well sort of - see below, but note that in addition to content filtering, the addition of msg_footer will probably break DKIM signatures.
If you put the following in pass_mime_types
multipart/alternative text/plain text/html
and set both collapse_alternatives and convert_html_to_plaintext to No, multipart messages which are not multipart/mixed (e.g., multipart/mixed, multipart/related and multipart/signed) will be handled according to filter_action. Messages which are multipart/alternative with only text/plain and text/html alternatives will be passed unchanged by content filtering as will single part messages of type text/plain or text/html.
Potential problems with this are:
- you may not want single part text/html on the list.
- some people sign their posts.
Because of 2), you need to add multipart/signed and application/pgp-signature to pass_mime_types, but that complicates the content filtering scenario because now a message with a structure like
multipart/signed text/plain application/pgp-signature image/jpeg
will be accepted by the list with the image/jpeg part removed rather than handled according to filter_action.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan