Ask whoever manages your domain to publish SPF, DKIM and DMARC records for your mailbox service, then send a test message to a Gmail address and check that all three show PASS.
Why it happens
Anyone can write any address in the “from” line of an email. That is how scams work. So services like Gmail and Outlook check whether a message really comes from the business it claims to come from. If they cannot tell, they play safe and send it to spam, or refuse it.
Since 2024 Google has made this formal: every sender must pass at least one of these checks, and businesses that send large volumes must pass all three.
The three checks, in plain words
| Name | What it says, in plain words |
|---|---|
| SPF | “These are the services allowed to send email for my domain.” A list published on your domain. |
| DKIM | “Every message I send carries this signature.” A digital seal the receiving service can verify. |
| DMARC | “If a message fails those checks, here is what to do with it.” Your instruction to the world: report it, quarantine it, or reject it. |
All three live in your domain settings, as small text records. Your mailbox service, Zoho or Google for example, gives the exact values to paste in.
How to check yours in two minutes
- Send an email from your business address to a personal Gmail address.
- Open it in Gmail on a computer, click the three dots next to the reply arrow, and choose Show original.
- Look at the lines for SPF, DKIM and DMARC near the top. You want to see PASS for each.
If any of them says FAIL or is missing, that is very likely your spam problem.
Other common causes
- Sending from two places. A website contact form or a newsletter tool that sends “from” your address but is not listed in your SPF.
- A new domain. Brand new domains have no reputation yet. Send normally for a few weeks before any bulk sending.
- Too many links or attachments in the first message to someone new.
- Bulk emails without an unsubscribe link. Large senders must offer one click unsubscribe.
The bonus: protection against fakes
DMARC does more than help delivery. Once it is set to quarantine or reject, other mail services stop accepting messages that pretend to come from your address. That makes it much harder for a scammer to write to your customers as you.
Further reading
Official documentation behind the technical guidance in this article.
