How to Avoid Spam Filters: 10 Tips for Better Inbox Placement

Getting past spam filters is both an art and a science. Here are 10 concrete steps to improve your inbox placement.

1. Authenticate Your Domain

SPF, DKIM, and DMARC are non-negotiable. Without them, Gmail and Outlook assume your email is spoofed. Check your authentication with a tool like MXToolbox.

2. Warm Up Your Account

Never send cold email from a brand new account. Warm up for at least 14-30 days before your first campaign.

3. Keep Volume Consistent

Sudden spikes in volume are a red flag. Ramp up gradually and maintain consistent daily volume. Don't send 500 emails one day and zero the next.

4. Avoid Spam Trigger Words

Words like "free," "guaranteed," "act now," and "limited offer" trigger spam filters. Write naturally, like you're emailing a colleague.

5. Personalize Beyond the Name

Generic emails with only {{first_name}} swapped in are increasingly filtered. Reference something specific about the recipient or their business.

6. Keep HTML Minimal

Heavy HTML, images, and tracking pixels raise spam scores. Use plain text or minimal formatting. A logo and one CTA button is plenty.

7. Include an Unsubscribe Link

One-click unsubscribe is legally required (CAN-SPAM, GDPR) and filters look for it. Make it prominent and functional.

8. Monitor Bounce Rates

A bounce rate above 5% is dangerous. Above 10% is catastrophic — pause immediately and clean your list. Use email verification before sending.

9. Send During Business Hours

Emails sent at 2am are statistically more likely to be spam. Schedule your campaigns for 9am-11am in the recipient's timezone.

10. Encourage Replies

Reply rates are the strongest positive signal to email providers. If recipients reply to your emails, your sender reputation improves dramatically. Write emails that invite responses.