Subject tag [Dovecot] is gone

[Mark Sapiro]

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:
1) you may not want single part text/html on the list.
2) 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 at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: OpenPGP digital signature
URL: <http://dovecot.org/pipermail/dovecot/attachments/20140610/b058be25/attachment.sig>