Why does my email land in spam?
Your email lands in spam because the receiving server does not trust your message, and that distrust almost always comes down to four causes: missing authentication (SPF, DKIM and DMARC), a sending domain with no reputation, a list full of dead addresses, and recipients who ignore your mail or report it as spam. All four can be fixed, and three of them can be sorted out before you send a single message.
How a spam filter actually decides
A spam filter does not read your text the way a person does. It adds up signals: is the sender technically valid, do we know this domain, how did recipients react last time, and only at the very end: what does the content look like. Each signal adds or removes points, and above a threshold the message goes to the Junk folder. That is why removing the word "free" from your subject line rarely helps. It is a drop in a score that is decided elsewhere.
1. No authentication
Without SPF, DKIM and DMARC the receiving server cannot check whether the message really comes from your domain. That is exactly the pattern of phishing and forgery, and it is treated accordingly. The large providers now require anyone who sends regularly to have all three records in place. How they work together is explained on our page about SPF, DKIM and DMARC. In practice you add them to your DNS once and never think about them again.
How to recognise it: your mail lands in spam with virtually every recipient, including colleagues and yourself, and it has been that way since day one. A configuration error behaves consistently.
2. A domain without reputation
If you send from a domain or IP address that has never sent mail before, you are a stranger. A thousand messages at once from such a domain is the classic spam pattern: a spammer registers a domain, sends as much as possible and disappears. You build reputation by starting gradually with recipients who open your mail. That process is called IP warming, and a good sending partner guides you through it.
How to recognise it: your first big newsletter from a new domain or a new provider arrived badly, while smaller sends before it reached the inbox without trouble.
3. A dirty list
Addresses that no longer exist produce bounces, and a high bounce rate is a strongly negative signal. Old lists also contain spam traps: addresses that providers deliberately leave lying around to see who sends carelessly. A five-year-old list that was never cleaned easily contains ten to twenty per cent dead addresses.
A real-world example: the CRM exports every contact that "was ever a customer" and the marketing team mails all of them. Half have changed jobs, some of the companies no longer exist. After that single send, even ordinary customer mail arrives worse for weeks.
How to recognise it: your bounce rate is above two per cent, or your delivery drops after every large campaign and recovers only slowly.
4. Poor engagement
Mail that is never opened or clicked, and above all mail that is reported as spam, pushes your next sends further away. Providers measure how recipients react: deleting without reading, moving to spam, or opening and replying. Two people in a thousand clicking "report spam" is already too many for a lot of filters.
How to recognise it: your open rate declines steadily, and the drop is concentrated at one provider, for example only at Gmail addresses.
What about the content?
Content matters less than most people think, but not nothing. A message that consists of one large image, shortened links, a subject line in capitals or a sender that does not match the reply address: each of those costs points. They are rarely the main cause, but often the final straw when everything else is already shaky.
What to do first
- Get SPF, DKIM and DMARC in order. One-off work that solves the most common problem.
- Remove addresses that have opened nothing in the past twelve months or ever produced a hard bounce.
- Send your system mail (order confirmations, invoices, password resets) through a different route than your campaigns, so a bad newsletter cannot drag your invoices down with it. Our page on transactional email explains how.
- Build up volume gradually after every change of domain or provider.
Want to know where you stand today? Our deliverability page explains how to follow delivery per domain, including bounces and rejections per receiving provider.
Frequently asked questions
Does my mail go to spam because of certain words?
Rarely. Word filters still exist, but they carry little weight compared with authentication and reputation. Only rewrite your copy once the technical side is in order.
How long does it take for my reputation to recover?
Count on a few weeks of consistent, clean sending. Reputation recovers more slowly than it breaks.
Can I see which folder my mail ended up in?
Not directly: the receiving server only reports that the message was accepted. You infer it from opens and clicks per provider, and from test addresses at the large providers.