Why Do Emails Go to Spam?
12 common reasons + actionable fixes for each
You hit send on an important email, but it never reaches the inbox. Sound familiar? Around 20% of legitimate emails never reach their destination—they land in spam or get blocked entirely.
Understanding why emails go to spam is the first step to fixing the problem. This guide covers the 12 most common reasons and gives you actionable fixes for each.
Quick Diagnosis
Not sure what's causing your spam issues? Start with the most common culprit: your email content. Use Sendable's free spam checker to instantly identify spam trigger words in your copy.
12 Reasons Emails Go to Spam
Your Email Contains Spam Trigger Words
Words like "free," "guarantee," "act now," and "limited time" trigger spam filters.
Poor Sender Reputation
Your domain or IP has been associated with spam, either from your sending or a shared IP.
Missing Email Authentication (SPF/DKIM/DMARC)
Email providers can't verify your identity, making your emails look suspicious.
High Bounce Rate
Sending to invalid addresses signals you have a poor-quality list.
Low Engagement Rates
If recipients don't open or engage with your emails, providers assume they're unwanted.
Misleading Subject Lines
Subject lines that don't match content or use deceptive tactics.
Too Many Images, Not Enough Text
Image-heavy emails with little text look like spam or phishing attempts.
Suspicious Links
URL shorteners, too many links, or links to blacklisted domains trigger filters.
No Unsubscribe Option
Marketing emails without unsubscribe links violate CAN-SPAM and get flagged.
Sending Too Fast or Too Much
Sudden spikes in volume or sending hundreds of emails per hour looks like a spam attack.
Recipients Marked You as Spam
Previous recipients have clicked "Report Spam" on your emails.
Using AI-Generated or Robotic Language
Generic, AI-sounding phrases signal mass emails and lack of personalization.
How to Diagnose Your Specific Issue
Not sure which of these issues is affecting you? Here's a diagnostic approach:
Step 1: Check Your Content First
Content issues are the most common and easiest to fix. Use a spam checker tool to scan your email for trigger words and AI-sounding phrases.
Step 2: Verify Technical Setup
Use tools like MxToolbox to check your SPF, DKIM, and DMARC records. All three should be properly configured and passing.
Step 3: Check Sender Reputation
Google Postmaster Tools shows your domain reputation with Gmail. Microsoft SNDS does the same for Outlook. Check both regularly.
Step 4: Review Sending Patterns
Look at your email volume, timing, and bounce rates. Sudden changes or high bounces often trigger spam filters.
Prevention Checklist
- ✓Check content for spam trigger words before every send
- ✓Maintain proper email authentication (SPF, DKIM, DMARC)
- ✓Clean your list regularly to remove invalid addresses
- ✓Monitor your sender reputation weekly
- ✓Keep sending volume consistent and gradual
- ✓Always include easy unsubscribe options
Start With Content Analysis
The fastest way to improve deliverability is to fix your email content. Check your emails for spam triggers in seconds with Sendable.
Try Free Spam Checker