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October 2, 2006

Gmail Improves False-Positive Spam Detection

New York Times quotes a report from Lyris, an email marketing firm that tracked 57,000 mails sent from 57 businesses and nonprofit organizations. Only 3% of these messages were mistakenly labeled as spam by Gmail. In the first quarter of 2006, a similar study concluded that 44.1% of the business messages were sent to the Spam folder, although customers chose to receive them.

Gmail's spam filters are adaptable, so they get better over time. In 2004, Slashdot asked "How good is Gmail's spam filter?" and someone responded:

"So far, no spam whatsoever has found its way into my inbox. However, the amount of false positives filtered into the spam folder is overwhelming.

For a while I wondered why I only got reports by email about 30-40% of my finished online auctions (link omitted, no free advertising here). Last week I accidentaly clicked on the spam folder, and there it was, dozens of FALSE POSITIVES."


  1. I have to say with regards to this, I've been very impressed. I get a lot of joke e-mails from friends, and so far only one (Out of about 3,000 in my joke folder) got false-positived. With regards to other e-mails, I very rarely have to either mark as spam, or mark as not-spam...

    It's such an uncommon thing, infact, that when I do have to do it, it stands out; which when you consider the amount of spam that is received (About 40+ messages a day for me, sadly) is quite remarkable.

    That being said, a couple of months back there was a brief spate of e-mails that got through which were spam but, because of their content (Apparently clips from books and such) did not get spam-filtered... but I don't have any problem with those now, and I've noticed that several have made it into the spam folder, so Google's adaptive filtering has done its usual impressive trick.

    On the whole, much better than most spam filters I've used, even the really expensive ones

  2. I don't know that I've ever received a false positive in my personal account.

  3. I am having problems with false positives (i.e., good messages being identified as spam).

  4. I'm getting crazy with the false positive issue GMAIL tags my company mails (and I'm talking of single messages and not bulk share).

    I don't know how to do.

    At least they could have implemented a sort of complex sender identification procedure (so spammer wouldn't be interested in following it) to avoid companies to suffer from this kind of terrible issue.

    I manage an Hotel and if a customer enquire me for an estimate, I send him a powerful HTML mail with all the rooms pictures....

    Well this mail is sistematically filtered and tagged as SPAM.

    No hided code, no bulk sends, no pictures only messages....

    Only an estimate.

    If someone may kindly inform me on how to convince the GMAIL Spam Filters to let my mails slip on the Inbox of its users, I'll be very grateful.

    Yes of course: my Hotel/B&B has got a name that can be misunderstood.

    The Name is Venice Penthouse.

    But should I change the company name to satisfy GMAIL criteria?

    I don't think so.

    My spamming mail (when you can write to) is

    Stefania Castelli

  5. In my case, I'm monitoring a website contact email account where there is only about 1 genuine email a week versus hundreds of spam messages.
    When that 1 message gets false-positived, as has been happening, I'm almost certain to miss it. And I don't get enough to enable the adaptive filtering to work.

    If there was a configurable filter available to override the spam detector when certain keywords occur, it would help a lot.