Filters and windmills

A colleague of mine was dealing with a client who is experiencing some difficulty delivering to the bulk folder. Said client spent much of a one hour phone call repeating “This is not how a free society works!!”
After the call my colleague commented, “I refuse to get ranty about filter systems.”
I know that filters, and the people who write and maintain them, are a frequent scapegoat for senders. The filters are always the problem, not anything the senders do.
Now, I’ll be the last person who will claim spam filters are perfect, they’re not. Filters sometimes do unexpected things, sometimes they do boneheaded things, sometimes they are broken.
We can’t forget, though, that filters perform a vital role in protecting users from malicious emails. Phishing emails, scams, fake products, viruses are a constant threat. Many end users don’t need to worry about this because filters are so good. But an unfiltered account can get thousands of scams and spams a day (ask me how I know).
Most of us in the delivery space can tell when a filter is working as intended and when there’s an underlying problem. And when the filter is working as intended there’s not a lot of use complaining about them. Ranting about filtering systems often delays a resolution. Senders that focus on what they can control tend to have more success reaching the inbox than those senders that focus on ranting about filtering systems.
Tilting at windmills doesn’t get the mail through.

What email metrics do you use?
One Click, Two Click, Red Click, Blue Click

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Every mailserver admin, whether managing a MTA for a corporation, an ISP or themselves inevitably looks at the question of false positives and false negatives. Some are more sensitive to false negatives and would rather block real mail than have to wade through a mailbox full of spam. Others are more sensitive to false positives and would rather deal with unfiltered spam than risk losing mail.
At the ISPs, many of these decisions aren’t made by one person, but the decisions are driven by the business philosophy, requirements and technology. The different consumer ISPs have different philosophies and these show in their spamfiltering.
Gmail, for instance, has a lot of faith in their ability to sort, classify and rank text. This is, after all, what Google does. Therefore, they accept most of the email delivered to Gmail users and then sort after the fact. This fits their technology, their available resources and their business philosophy. They leave as much filtering at the enduser level as they can.
Yahoo, on the other hand, chooses to filter mail at the MTA. While their spamfoldering algorithms are good, they don’t want to waste CPU and filtering effort on mail that they think may be spam. So, they choose to block heavily at the edge, going so far as to rate limit senders that they don’t know about the mail. Endusers are protected from malicious mail and senders have the ability to retry mail until it is accepted.
The same types of entries could be written about Hotmail or AOL. They could even be written about the various spam filter vendors and blocklists. Every company has their own way of doing things and their way reflects their underlying business philosophy.

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As usually, I think everyone else is a little bit right and a little bit wrong.
The words and phrases posted by Hubspot are pulled out of the Spamassassin rule set. Using those words or exact phrases will cause a spam score to go up, sometimes by a little (0.5 points) and sometimes by a lot (3+ points). Most spamassassin installations consider anything with more than 5 points to be spam so a 3 point score for a subject line may cause mail to be filtered.
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