On 23 Nov, Nancy McGough wrote:
| On 23 Nov 2002 dman(_at_)nomotek(_dot_)com (dman(_at_)nomotek(_dot_)com)
wrote:
| > Don Hammond <procmail(_at_)tradersdata(_dot_)com> wrote:
| >
| > > I don't want to speak for Dallman, but the recipe is not searching the
| > > body. The thinking on the filter seems to be, if it's plain text or html
| > > AND base 64 encoded, then it's spam. There would be no reason, I guess,
| > > to encode plain text other than to circumvent content filters. Who does
| > > that? The bottom feeders.
| >
| > Exactly. Thanks, Don.
|
|
| I don't think it's just the bottom feeders that do this. If a
| message contains a high ascii character, such as the GB Pound
| symbol, and the mail client or the mail transport only does 7bit,
| then the message will be MIME encoded, either with
| quoted-printable or base-64. I think that Mulberry and Cyrus IMAP
| server always convert to 7bit and thus always encode messages
| with 8bit characters (and this is one of the few things I don't
| like about these products). I think there are other clients and
| servers that do this too.
My understanding of MIME, encoding, and so on is sketchy at best. But
wouldn't it be typical for the server to add a header if the encoding
was done locally? In my saved mail there are X-MIME-Autoconverted:
headers indicating conversions done by my server (sendmail). I retrieve
mail directly from the spool without IMAP or POP, so it's not exactly
the same as what you're talking about, but do those servers add a header
when they've "messed" with your mail too? If so, and if so desired, it
should be trivial to add a condition to exclude those messages. Then
the recipe in question would match messages encoded when sent, which
would seem to correlate pretty well (at least today) with spam.
--
Reply to list please, or append "8" to "procmail" in address if you must.
Spammers' unrelenting address harvesting forces me to this...reluctantly.
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