Why Are My Emails Going to Spam?
If your emails are landing in spam or being quarantined, work through this checklist to identify and fix the issue.
Check your authentication records
Section titled “Check your authentication records”Make sure your domain has all three authentication records properly configured:
- SPF: Automatically set up when you verify your domain with Resend. Verify it is still present with dns.email.
- DKIM: Also set up during domain verification. Confirm with dns.email.
- DMARC: Not automatically set up, but strongly recommended. See DMARC for setup instructions.
Use Deliverability Insights
Section titled “Use Deliverability Insights”If you sent the email through Resend, open the email in your dashboard and review Deliverability Insights.
Deliverability Insights runs a set of best-practice checks against your email and flags issues that may affect inbox placement. Pay close attention to warnings about:
- Links that do not match your sending domain
- Missing or invalid DMARC
- Missing plain text versions
- Using
no-replysender addresses - Large email body size
- Open or click tracking for sensitive emails
Check the spam banner
Section titled “Check the spam banner”When an email lands in spam, providers like Gmail display a banner explaining why. Here are common messages and what they mean:
| Banner message | What it means | Fix |
|---|---|---|
| "It's similar to messages that were identified as spam in the past." | Content is triggering spam filters | Simplify your email content and remove excessive links, images, or marketing language |
| "This message seems dangerous" | A URL or content was flagged as malicious | Review the links and content in your email for anything that might be flagged as unsafe |
Check your domain reputation
Section titled “Check your domain reputation”- Use Google Postmaster Tools to see your domain and IP reputation with Gmail.
- If your domain is new, you may need to warm it up by starting with low volume and increasing over time. See our Domain and/or IP Warm-up Guide.
Corporate email filters
Section titled “Corporate email filters”Some recipients use enterprise email security services like Mimecast, Proofpoint, or Barracuda. These services apply their own filtering on top of standard spam checks.
If your emails are being blocked by a specific corporate recipient:
- Ask the recipient to check their quarantine or junk folder and allowlist your sending domain.
- These filters often block based on domain age, content patterns, or URL reputation. The fixes in the steps above still apply.
Review your sending practices
Section titled “Review your sending practices”- Send from a dedicated address per email type, such as
notifications@for transactional emails andupdates@for marketing emails. For more guidance on domain setup, review Is it better to send emails from a subdomain or the root domain?. - Do not send to purchased lists or addresses that have not opted in. If you are unsure what qualifies as permission, review What counts as email consent?.
- Include a visible unsubscribe link in marketing emails.
- Keep HTML simple. Heavy formatting and image-only emails are more likely to trigger filters.
Get more help
Section titled “Get more help”If you have worked through the steps above and still need help, our support team is happy to take a closer look. Contact us through our support form and share any relevant details about the issue, such as the recipient provider, sending domain, and what you have already tried.