Bug 6182 - MPART_ALT_DIFF_COUNT trips on valid Apple Mail messages
Summary: MPART_ALT_DIFF_COUNT trips on valid Apple Mail messages
Status: RESOLVED INVALID
Alias: None
Product: Spamassassin
Classification: Unclassified
Component: Rules (show other bugs)
Version: 3.2.5
Hardware: All All
: P5 minor
Target Milestone: Undefined
Assignee: SpamAssassin Developer Mailing List
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2009-08-20 14:30 UTC by James Ralston
Modified: 2021-04-17 04:19 UTC (History)
3 users (show)



Attachment Type Modified Status Actions Submitter/CLA Status
apple info application/x-php None adrian [NoCLA]

Note You need to log in before you can comment on or make changes to this bug.
Description James Ralston 2009-08-20 14:30:45 UTC
We've recently (as of 2009-06 and 2009-07) received valid ham messages for which the MPART_ALT_DIFF_COUNT test fires.

The X-Mailer header is:

    X-Mailer: Apple Mail (2.935.3)

The problem is that the user replied to a message with this MIME structure:

multipart/signed
  multipart/mixed
    text/plain
    text/rtf
    text/plain
  application/pgp-signature

When the sender did so, Apple Mail constructed a message like this:

multipart/signed
  multipart/alternative
    text/plain*
    multipart/mixed
      text/html*
      text/rtf
      text/html
  application/pgp-signature

The asterisks denote the parts that were different encodings (text/plain versus text/html) of the same content.

Of course, the sane thing to do would've been this:

multipart/signed
  multipart/mixed
    multipart/alternative
      text/plain*
      text/html*
    text/rtf
    text/html
  application/pgp-signature

But alas, that's not what "Apple Mail (2.935.3)" did. :(

Is there any chance that the MPART_ALT_DIFF_COUNT could be tweaked to avoid penalizing Apple Mail's stupidity?

Alas, I cannot attach the original messages, but I could manually construct sample messages with the same bizarre MIME structure...
Comment 1 adrian 2016-09-12 04:24:01 UTC
Created attachment 5403 [details]
apple info
Comment 2 Joe Quinn 2016-09-12 12:33:44 UTC
Don't spam the list with irrelevant attachments.
Comment 3 Joe Quinn 2016-09-12 12:34:26 UTC
Meant to say the bug tracker, but it's also spamming the dev list.
Comment 4 Bill Cole 2021-04-17 04:19:46 UTC
Not a bug. Rules hitting some ham are to be expected. MPART_ALT_DIFF_COUNT is currently scored well below the threshold for all 4 rulesets, so no action is needed. Had there been a shareable sample which scored over 5 when this was submitted, it may have merited attention to limit the score to a lower level or perhaps even adapt to what Mail.app was doing at that time, but no sample exists. 

Also, in a dozen years of inaction, this may not even be an issue of any sort as both Mail.app and SpamAssassin have advanced substantially.