Why does my email end up in spam? (and how to prevent it)
Why does my mail end up in spam?
Large mail providers receive enormous amounts of unwanted mail every day. To separate that from genuine messages, their filters look at a series of signals. If those are missing or don't check out, your message disappears into the spam or junk folder, exactly as many users describe it: messages that were sent neatly, but end up among the unwanted mail at the recipient's end.
The four causes that come up most often:
- Missing or incorrect authentication. Without correct SPF, DKIM and DMARC, the receiving server can't check whether you really are allowed to send on behalf of your domain.
- Poor IP reputation. If you send via a server whose IP address has been used for spam before (for example shared, cheap hosting), you inherit that bad name.
- The content of your message. Lots of links, only a large image without text, or words that typically appear in spam, increase your risk.
- Send volume and pattern. Suddenly hundreds of mails at once from an address that normally sends little looks suspicious.
Doing everything right and still spam?
This is the frustrating situation many entrepreneurs get stuck in: neat text, real customers, no strange links, and yet the mail ends up in spam time after time. In nine out of ten cases the problem then lies in the technology behind the scenes.
Two things weigh heaviest. The first is authentication. SPF, DKIM and DMARC are agreements set out via your DNS; together they prove to the recipient that a message really comes from your domain and wasn't altered along the way. Want to know what each part does, then read the explanation about what SPF is, what DKIM is and what DMARC is.
The second is IP reputation: the "name" of the server you send from. If you're on a shared IP address with many spammers, your deliverability suffers, however neatly you mail yourself. You can read more about that in the piece on IP reputation and email.
Since 2024 these signals weigh extra heavily: large mail providers require anyone who sends in bulk to authenticate their email correctly, otherwise the mail is refused or labelled as spam. What that concretely means is set out in email authentication: why it's now mandatory.
How to fix it
The approach splits into two parts: what you control yourself, and what your provider should arrange.
What you do yourself:
- Write ordinary, personal mails. Avoid an avalanche of links and "free!" language.
- Send only to people who expect your mail. If you don't know an address, don't send.
- Build volume up calmly instead of sending hundreds of messages at once.
What your provider should arrange:
- Setting up SPF, DKIM and DMARC correctly and keeping them up to date. Want to combine it yourself, then follow the guide on setting up SPF, DKIM and DMARC together.
- Sending via IP addresses with a good reputation, and guarding that reputation.
- Setting up a correct reverse DNS (PTR), so the IP address points neatly to your mail server.
Checklist: your mail out of spam
Go through these points if your mail keeps getting stuck:
- SPF, DKIM and DMARC are correctly set up for your domain.
- You send via a server with a good IP reputation.
- Reverse DNS (PTR) points to your mail server.
- Your message is personal, with a balance between text and image.
- You send only to recipients who expect your mail.
- For larger sends you build the volume up gradually.
If your email isn't coming in at all anymore, a broader approach is needed. In that case work through the checklist for email that doesn't arrive.
How Mailflux handles this for you
With Mailflux you don't have to tinker with deliverability yourself. We manage SPF, DKIM and DMARC and guard the IP reputation of our sending servers, so your mail sends the right signals to the recipient. On top of that, every plan filters with machine learning against spam, phishing and malware, and comes with antivirus, antispam and antimalware as standard.
You get professional email on your own domain, hosted in Europe and GDPR-compliant, with automatic backups and optional two-factor authentication. That way your attention stays on your work instead of on DNS records. More about the broader approach can be read in the overview on email deliverability.
FAQ
Frequently asked questions
Why does my mail end up in spam while I'm doing everything right?
Usually it's the technology behind the scenes, not your text. Missing or incorrect SPF, DKIM and DMARC, or a sending server with a weak IP reputation, give the recipient too little trust. Fix those signals and the problem usually resolves.
Can I see for myself why my mail ends up in spam?
Partly. You can check whether SPF, DKIM and DMARC are set up for your domain and whether your IP isn't on a blocklist. The deeper causes, such as reputation and alignment, require more insight. A provider that manages this takes that investigative work off your hands.
Does an email address on my own domain help against spam?
Yes, indirectly. Your own domain with correct authentication looks more trustworthy than a free address, and you keep control over SPF, DKIM and DMARC yourself. That way you build your own, clean reputation instead of sharing one with unknown senders.