On Thu, 17 Dec 2020, John Hardin wrote:
On Thu, 17 Dec 2020, @lbutlr wrote:
On 16 Dec 2020, at 23:21, Loren Wilton <lwil...@earthlink.net> wrote:
I just got a batch of spams containing
<span style="display:none">
Interesting. I remember in the early days of html spam there were various
rules to tag messages as spam when they had content that did not display.
(Possibly pre-SpamAssasin or at least pre my use of SpamAssasin).
Such rules are there. Unfortunately, for whatever reason, lots of ham uses
"invisible" text so it's not useful as a spam sign by itself and it's hard to
come up with any useful combination rules.
I think I may have figured it out - tracking images. Like:
<img src="long unique tracking uri" width="0" height="0" border="0" style="visibility:
hidden !important; display:none !important; max-height: 0; width: 0; line-height: 0; mso-hide: all;">
The src link gets visited to retrieve the image so the message is tracked,
but the display of the image is suppressed.
--
John Hardin KA7OHZ http://www.impsec.org/~jhardin/
jhar...@impsec.org pgpk -a jhar...@impsec.org
key: 0xB8732E79 -- 2D8C 34F4 6411 F507 136C AF76 D822 E6E6 B873 2E79
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"Bother," said Pooh as he struggled with /etc/sendmail.cf, "it never
does quite what I want. I wish Christopher Robin was here."
-- Peter da Silva in a.s.r
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3 days until Christmas
