You send a quote to a new client and hear nothing back. A week later they find it in their spam folder. For many small businesses this is a weekly problem, and in most cases the cause is not what you wrote. It is that the receiving mail server cannot confirm the email really came from you.
Three DNS records solve this: SPF, DKIM and DMARC. They live in your domain’s DNS settings, the same place your website records live, and they take minutes to add once you know the right values.
SPF: who is allowed to send for your domain
SPF (Sender Policy Framework) is a TXT record that lists the services allowed to send email using your domain, for example Google Workspace, Microsoft 365, your web host and your newsletter tool. When an email arrives claiming to be from you@yourcompany.com, the receiving server checks whether it came from one of those services.
Two common mistakes: having two separate SPF records (you are only allowed one, so combine them), and forgetting to include a tool you send from, such as your website’s contact form or your invoicing software.
DKIM: a signature that proves the email was not changed
DKIM (DomainKeys Identified Mail) adds a digital signature to every email you send. Your email provider gives you a public key to publish in your DNS, and receiving servers use it to check the signature. If it matches, they know the message really came from your provider and was not altered on the way.
DMARC: what to do when checks fail
DMARC ties SPF and DKIM together. It tells receiving servers what to do with email that fails the checks, whether to deliver it, send it to spam or reject it, and it can send you reports showing who is sending email using your domain. A sensible starting point is a monitoring-only policy (p=none), then moving to quarantine or reject once you are confident every legitimate sender is set up.
Why this matters more now
Since 2024, Google and Yahoo have required senders to authenticate their email, with stricter rules for anyone sending in bulk. Many other providers have followed. Domains without these records are far more likely to see their mail filtered or rejected.
Other reasons emails go to spam
- Sending from a free address (Gmail, Yahoo) instead of your own domain
- Your domain or server’s IP address is on a blocklist, often after a hacked website sent spam
- Website contact forms sending through the server’s default mail instead of a proper SMTP service
- Messages that are mostly images, link shorteners or heavy sales wording
How to check your domain
Free tools such as MXToolbox can show whether your SPF, DKIM and DMARC records exist and are valid. If the results are confusing, or you are not sure which services send email for your business, we can help. We set up business email and fix delivery problems for companies in Nigeria, the UK and the US. Tell us what is happening and we will check your domain.
