Why Your Emails Go to Spam and How to Fix It
If your business emails land in junk folders, there is almost always a reason you can find and fix. A step-by-step checklist from DNS records to content habits.
Nothing is more frustrating than discovering that a quote, an invoice or a reply sat in a customer's junk folder for three days. The good news is that emails rarely go to spam for mysterious reasons. Work through the checklist below from top to bottom, because the most common causes are also the cheapest to fix.
Work through the checklist
Step 1: confirm the problem is real
Ask the recipient to check their junk folder and tell you which provider they use. Then test with a few accounts at different providers. If mail goes to spam at only one provider, the cause is probably that provider's filtering of your domain or IP. If it goes to spam everywhere, suspect your DNS records or content.
Step 2: read the message headers
In the received message, open the full headers (often called "show original" or "view source"). Look for an authentication results line. It should say that SPF, DKIM and DMARC pass. A line showing fail, softfail or none points to your cause.
Step 3: fix SPF, DKIM and DMARC
- SPF: make sure there is exactly one SPF record on the domain and that it includes every service that sends as you: your mail host, a newsletter tool, a CRM, a website form service.
- DKIM: make sure your mail server signs outgoing messages and that the public key is published in DNS at the correct selector.
- DMARC: publish a record, even a monitoring-only one, so providers see that you are managing the domain.
Our in-depth articles on SPF, DKIM and DMARC cover the details and the common mistakes.
Step 4: check your sending IP and domain
If your mail goes out through a server that also sends for many other customers, another customer may have damaged the IP's reputation. Check whether the sending IP appears on public blocklists, and make sure it has a matching reverse DNS entry. If your domain is brand new, expect more caution from filters until it builds a history. Start with low volumes of real, wanted conversation.
Step 5: look at your content
Content is rarely the sole cause, but it can tip a borderline message into spam. Review:
- Subject lines that shout, overpromise or use excessive punctuation.
- Messages containing only a large image, or only a link.
- Links that use URL shorteners or redirect through unrelated domains.
- Attachments of unusual types, such as zipped executables.
- HTML that is broken or copied from a word processor.
Write like a person. A short plain message that clearly says who you are and why you are writing is hard to beat.
Step 6: check the list, not just the message
For newsletters and campaigns, the biggest cause of junk placement is sending to people who do not expect the mail. Use opt-in sign-ups, include a visible unsubscribe link, remove addresses that bounce, and stop mailing people who never engage. Complaints from even a small share of recipients can harm your reputation with a provider.
Step 7: check for a compromised account
If your mail suddenly started going to spam with no change on your side, look for signs that an account was hacked. Check the sent folder for messages you did not write, look at login activity if your host provides it, and review mail forwarding rules. Change the password and enable stronger security. A compromised mailbox can send thousands of spam messages in an hour and ruin your reputation.
Step 8: ask the recipient to help
If a particular customer keeps missing your mail, ask them to mark one of your messages as "not spam" and add your address to their contacts. This teaches their filter that you are a legitimate sender. It does not replace correct DNS records, but it can fix a stubborn individual case.
A quick diagnostic table
| Symptom | Likely cause |
|---|---|
| Spam at every provider | Missing or failing SPF, DKIM, DMARC |
| Spam at one provider only | Provider-specific reputation or filtering |
| Bounces with a blocklist message | Sending IP listed |
| Sudden change with no edits | Compromised account or neighbour on a shared IP |
| Only newsletters affected | List quality, complaints, content |
| Website form emails missing | Sending without authentication; see our contact form article |
What not to do, and how to keep it fixed
- Do not buy lists to "grow" quickly.
- Do not keep sending the same message repeatedly hoping one gets through.
- Do not publish multiple conflicting SPF records while experimenting.
Once your mail is landing correctly, protect that result. Review your DNS records whenever you add a new tool that sends email on your behalf, read your DMARC reports now and then, and use a strong, unique password on every mailbox. A short regular check is far cheaper than discovering weeks later that customers never saw your messages.
Reliable delivery with Zebra Hosting
Most spam-folder cases are settled by getting authentication and basic hygiene right, and that is much easier on a properly configured host. Zebra Hosting's team can help check your records, and support is available in 17 languages. See the email hosting plans, or reach us through the contact page if you want a second pair of eyes on your headers.
