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.