Misinformation on filters

I’ve seen reports that someone is asserting that utm=COVID19 in URLs results in all mail going to bulk at multiple ISPs. This is the type of thing that someone says is true and dozens of folks believe it and thus a “deliverability phact” is born. For a plethora of reasons, this doesn’t pass the sniff test. Don’t believe everything you read on the internet.

It’s very tempting to identify this One Simple Trick to get your email into the inbox. Change this font. Take out this UTM. Change this hostname. And, in some cases it may even work for a time.

But, look, if filters really were that simple they’d be wholly ineffective. Not just slightly ineffective but wholly ineffective. Anything that is easy to test can be defeated, and spammers test as much or even more than marketers do.

Don’t believe me? Over a decade ago I was invited to a meeting with a “marketing company” based out of San Francisco. After I got there and signed the NDA, they explained their strategy to get mail into Hotmail. Starting at 5pm they would have their content staff start writing emails and sending them to Hotmail. They’d test and test and test until one of them got into the inbox. Once they found content that would get through the filters, they’d turn on the floodgates and send as much mail as they could until the filters caught up. They’d do this all night, every night. (They were shut down by the FTC not long after I declined to work with them.)

It’s naive to believe that filters would be so transparent and think they’d still work. Anything so simple is going to be discovered and exploited by the spammers. Don’t fall prey to this kind of deliverability nonsense. Think about what the bad guys would do if this were true. And then remember that the bad guys have a lot of practice exploiting naive filters.

Related Posts

Their network, their rules

Much of the equipment and wires that the internet runs on is privately owned, nor is it a public utility in the traditional sense. The owners of the property have a lot of leeway to do what they like with that property. Yes, there are standards, but the standards are about interoperability. They describe things you have to do in order to exchange traffic with other entities. They do not dictate internal policies or processes.

Read More

Filters working as intended

One of the toughest deliverability problems to deal with is when mail is blocked or going to spam because the filters are working as intended. Often the underlying issue is a lack of permission.

Read More

Return Path on Content Filtering

Return Path have an interesting post up about content filtering. I like the model of 3 different kinds of filters, in fact it’s one I’ve been using with clients for over 18 months. Spamfiltering isn’t really about one number or one filter result, it’s a complex interaction of lots of different heuristics designed to answer the question: do recipients want this kind of mail?

Read More