Why Your Emails Are Going to Spam: SPF, DKIM and DMARC Explained in Plain Words

Emails going to spam usually means the receiving server cannot confirm they really come from your domain. Add SPF and DKIM records, then DMARC, send website form emails through an authenticated service, and keep complaints low. Gmail's sender guidelines require all senders to use SPF or DKIM, and bulk senders of 5,000+ a day to use both plus DMARC.

Why Are Emails Going to Spam?

A customer says your quote never arrived. Your contact form "works" but enquiries vanish. Invoices land in clients' junk folders. When emails are going to spam, the cause is usually not the wording of the message but missing proof that the email genuinely came from your domain. Mailbox providers such as Gmail and Outlook check for that proof, and without it they treat messages with suspicion.

For the search side of the same problems, read our guide to appearing on Google.

What Are SPF, DKIM and DMARC?

All three are text records added to your domain's DNS. Your email provider, such as Google Workspace, Zoho or your host, gives you the exact values.

What Does Gmail Require?

Google's email sender guidelines, in effect since 1 February 2024, set out requirements:

• All senders: authenticate with SPF or DKIM, have valid forward and reverse DNS, use TLS, keep the spam rate reported in Postmaster Tools below 0.30%, and follow standard message formatting.
• Senders of 5,000 or more messages a day to Gmail: use both SPF and DKIM, set up DMARC (a policy of "none" is acceptable), align the From domain with SPF or DKIM, and support one-click unsubscribe for marketing messages.

Most small businesses send far fewer than 5,000 a day, but setting up all three records is still the best protection.

Why Do Website Form Emails Go to Spam?

Many websites send form notifications using the web server's built-in mail function, from an address like wordpress@yourdomain, without SPF or DKIM covering that server. Receivers see an unauthenticated message and filter it. The fix is to send through an authenticated route: your email provider's SMTP settings, or a transactional email service, with the sending domain authenticated. Our contact form guide covers related form problems.

How Do You Fix It Step by Step?

1. List every service that sends email for your domain: mailbox provider, website, invoicing software, newsletter tool.
2. Create one SPF record that includes all of them; a domain should have only one SPF record.
3. Enable DKIM in each sending service and add the keys it gives you to DNS.
4. Add a DMARC record, starting with a monitoring policy, and read the reports for a few weeks.
5. Switch website forms to authenticated sending.
6. Test by sending to Gmail and Outlook addresses and checking the message headers show SPF, DKIM and DMARC passing.

What Else Can Cause Spam Filtering?

• Sending from a shared hosting server with a poor reputation.
• Bulk emails to people who never agreed to receive them, leading to complaints.
• Misleading subject lines or link shorteners.
• A newly registered domain sending large volumes suddenly.

What About Newsletters and Bulk Messages?

Send newsletters through a dedicated email marketing service rather than your normal mailbox, so bulk sending does not damage the reputation of the address you use for quotes and invoices. Authenticate the service with your domain, warm up a new list slowly, and remove addresses that bounce. Sending a sudden large batch from a new domain is a common way to land everything in spam.

Do Marketing Emails Need Consent?

Yes, in most places. Send newsletters only to people who opted in, include a clear unsubscribe link, and remove people who ask. Complaints are one of the strongest signals spam filters use.

Getting It Fixed

Setting up SPF, DKIM, DMARC and authenticated form email is part of every website we build from Rs 40,500, and of our care plans from Rs 7,200 a month. See our guide to business email on your own domain or our pricing page.

Frequently Asked Questions

1. Google — Email sender guidelines
2. Google Workspace Admin Help — Set up SPF, DKIM and DMARC
3. Cloudflare Learning — What are DMARC, DKIM and SPF?

How we researched this: Gmail requirements, the 1 February 2024 date, the 0.30% spam rate and the 5,000-message threshold come from Google's email sender guidelines, checked 30 October 2026. The plain-words analogies and fix steps are editorial. Our prices come from the published list.