Filter for email tracking pixels?

Discussion in 'Custom Filters' started by Cris, Apr 2, 2017.

  1. Cris

    Cris New Member

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    I haven't delved into custom filters, so don't know what they're capable of. In principle, do the filter rules have what it takes to prevent an email client from downloading tracking pixels in html emails?

    The kind of rules I'd have in mind might be something like:
    • disallow download of images from urls containing 'track' after the hostname
    • disallow IMG tags with width & height of 1px
    They wouldn't have to be perfect -- certainly a few false positives would be fine. And I can write the rules myself. But I'd like to know if it's possible before poring over the docs.
     
  2. avatar

    avatar Administrator Staff Member Administrator

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    That's rather easy:
    Code:
    ||*/track
    And that's not that easy.

    The straightforward way would be to use $$ rules:
    Code:
    $$img[height="1px"][width="1px"]
    But I am not sure about it, it might be better to take a look at the real email example first.
     
  3. Cris

    Cris New Member

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    Thanks Andrey, that's a very helpful start.
     
  4. lexvo

    lexvo New Member

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    Cris, I know this is an old thread, but did you manage to do some email tracking filtering? I'd like to do the same and maybe you have some experience to share :)
     
  5. avatar

    avatar Administrator Staff Member Administrator

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    Spyware filter is not that bad, we're adding known email tracking pixels there.

    Tbh, I suppose that it's too hard to handle it with a generic rule, so we have to discover & add trackers one by one.
     
    lexvo likes this.
  6. lexvo

    lexvo New Member

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    Thank you! I understand that there are many different email trackers, applying filters will be a lot of work. But it is good to know that there are email tracking filters in the Spyware filter. Saves me work trying to make my own filters :)