The Real Reason Your Emails Land in Spam
"Why did my email go to spam?" is one of those questions that almost never has a single, clean answer, no matter how much people want one. Modern filters weigh dozens of small signals together into a score, and cross a threshold — which is why two nearly identical emails can land in completely different places for reasons that have nothing to do with what you wrote.
Signals that actually matter
- Sender authentication — missing or broken SPF/DKIM/DMARC on a custom domain is one of the heaviest signals I've seen. Our explainer covers this if you send from your own domain.
- Sender reputation — a history of your address getting marked spam, ignored, or deleted unread quietly drags your standing down over time.
- Engagement — providers like Gmail genuinely weigh whether people open and reply to your mail. Send enough that nobody engages with, and even a "clean" account trends toward spam eventually.
- Content patterns — too many links, urgent language ("ACT NOW"), ALL CAPS, image-heavy mail with barely any text. All of it nudges the score.
- Volume changes — a sudden spike from an account that normally sends a handful of emails a day looks like compromise to automated systems, even when it's completely legitimate.
What matters less than people think
One "spammy-sounding" word in a subject line rarely decides anything on its own — filters weigh combinations, not individual words. Chasing a specific banned-word list is mostly a holdover from much older, cruder filtering technology.
If it's personal mail, not bulk
Ask the recipient to mark it "not spam" and add you to contacts. That single action corrects a filter's read on your relationship faster than almost anything else. If it's happening across many different recipients, the problem is more likely your sending domain's reputation or authentication setup, not any one relationship.