Your emails go to spam mostly because the receiving mail service can't confirm they really came from your domain. Since 2024 Gmail and Yahoo, and since May 2025 Microsoft's Outlook.com, check three DNS records on every message: SPF, DKIM and DMARC. If any of them is missing or wrong, your email is junked or refused outright.
What to check first
- Is it every email, or only some? If only invoices from your accounting software or messages from your website go to spam, that sender isn't set up for your domain.
- Do you get a bounce? A message such as
550 5.7.515 Access deniedor "message not authenticated" points straight at SPF, DKIM or DMARC. - Has anything changed? A new website, a domain move or a new email provider often wipes or breaks the records.
The usual causes
No DMARC record, or SPF and DKIM that don't line up with your domain. Large providers now expect all three. Too many services in SPF: SPF allows only ten DNS lookups, and businesses using Microsoft 365, Mailchimp, Xero and a booking system can easily go over without noticing. Website forms sending through the server's own mail, which isn't authenticated as you. A compromised mailbox sending spam, which damages your domain's reputation.
How to fix it
- List every service that sends email as your domain.
- Publish one correct SPF record that includes them all, within the lookup limit.
- Turn on DKIM signing in each service, using its own keys.
- Add a DMARC record, start by monitoring, then move to quarantine and reject once everything passes.
- Send test messages to Gmail and Outlook and check the headers say
pass.
If that sounds like a job for someone else, it's exactly what our same-day email deliverability fix covers.
