Why are my emails going to spam?
By Ash, Founder, HosteazePublished 2 min read
The short answer
The most common reason is missing or broken email authentication. If your domain has no SPF, DKIM or DMARC records, Gmail and Outlook can't prove the email is really from you. After that come a poor sender reputation, a shared server with a bad history, and messages that look like marketing. Check authentication first.
If your quotes, invoices or booking confirmations keep ending up in junk, you're not imagining it, and it's rarely bad luck. Mailbox providers like Gmail and Outlook decide where each email goes based on a handful of checks. Fail the important ones and you go to spam however polite your message is.
How do I find out why my emails are going to spam?
Look at the evidence before changing anything:
- Send an email from your business address to a personal Gmail account.
- If it lands in spam, open it, click the three dots and choose Show original.
- Look at the lines for SPF, DKIM and DMARC near the top. Each should say
PASS. - For other providers, paste the full message headers into the free Google Admin Toolbox Messageheader tool, which highlights failures.
Anything that says FAIL, SOFTFAIL or NONE is your first job.
Is it my email authentication?
Most of the time, yes. Since February 2024, Google has required everyone sending to Gmail to have at least SPF or DKIM, and bulk senders need DMARC too. Mail that fails can be sent to spam or rejected outright.
The usual culprits:
- No SPF record, or two SPF records (which breaks SPF entirely)
- DKIM never switched on at your email provider
- A newsletter or invoicing tool sending as your domain without being covered by SPF or DKIM
- An SPF record over the 10-lookup limit, covered in fixing "too many DNS lookups"
The fix is three DNS records added in the right order. Follow how to set up SPF, DKIM and DMARC.
What if authentication passes and I still go to spam?
Then it's about reputation or content. Work through these:
| Likely cause | How to tell | What to do |
|---|---|---|
| Spam complaints | Google Postmaster Tools shows a spam rate | Keep it below 0.1%. Google treats 0.3% or higher as a serious problem. Stop emailing people who didn't ask to hear from you. |
| A brand-new domain | The domain is weeks old | Start with small volumes to people who expect your email, and build up over a few weeks. |
| A blocklisted server | Your sending IP appears on a public blocklist | Ask your email provider to check. On shared servers, one bad neighbour can affect everyone. |
| Marketing-style content | Lots of images, links, capitals or "FREE" | Write like a person. Plain text with one link usually beats a glossy template. |
| No unsubscribe link | It's a newsletter | Marketing email needs a clear unsubscribe link, and bulk senders to Gmail need one-click unsubscribe. |
Does sending from Gmail or Outlook.com help?
It can mask the problem, but it isn't a fix. Sending business email from a free address looks less professional, and it doesn't help when your website's contact form or shop sends from your domain. Fixing your own domain's records solves both.
One last thing for UK and EU businesses: marketing emails usually need the recipient's consent under PECR and GDPR (existing customers can be an exception if you gave them a chance to opt out). Emailing people who never signed up is the fastest way to collect spam complaints, and those hurt every email you send afterwards, including the invoices.
Frequently asked questions
Why do my emails go to spam for one person but not others?
Each mailbox provider judges email differently, and individual recipients train their own filters. If one person once marked you as spam, or their company runs a strict filter, your mail can land in junk only for them. Ask them to mark it "not spam" and add you to their contacts.
Will a spam checker tool fix the problem?
It can tell you what's wrong, not fix it. Sending a test message to a free checker and reading its report is a quick way to spot missing SPF, DKIM or DMARC.
How long does it take to get out of spam?
Fixing authentication helps as soon as the DNS records are live, usually within hours. Rebuilding a damaged sending reputation takes longer, often several weeks of steady, wanted email.
