Somewhere out there is a blog post with “473 spam trigger words to avoid in 2026,” and it is wasting everyone’s time. The idea dates to the early 2000s, when naive keyword and Bayesian filters really did score messages word by word. Filtering has moved on; the listicles haven’t.
What filters actually weigh
Modern spam filtering is dominated by who is sending, not which words they used:
- Sender reputation—complaint rates (stay under 0.08%; 0.3% is where Gmail and Yahoo consider you unacceptable), bounce rates (under 4%), and the consistency of your sending patterns.
- Authentication—SPF, DKIM, and DMARC in order and aligned. Missing records hurt you more than any adjective ever will.
- Engagement—do recipients open, read, reply, and keep your mail? Or delete unread and hit “report spam”?
A trusted sender can put “free” in every sentence and land in the inbox. An untrusted sender gets filtered writing like a tax attorney. The words were never the variable.
Where content still matters
Deleting words from a list is cargo cult; these content signals are real:
- Misleading subject lines. A subject that doesn’t match the body erodes trust with recipients and filters—and deceptive subjects are a straight-up CAN-SPAM violation.
- Link hygiene. URLs and redirects should align with your sending domain. Mismatched links, sketchy shorteners, or a domain that’s landed on a blocklist like Spamhaus will hurt you regardless of prose.
- Overall coherence. All-images-no-text, invisible text, deliberate misspellings to dodge imagined filters—these are spammer fingerprints. Writing normally is the optimization.
The honest test
If your mail is going to spam, the answer is in your authentication, your list quality, and your engagement—start with why emails go to spam, not a thesaurus. Write like a human with something worth saying, to people who asked to hear it. That’s the whole trick.