Avoiding Spam Filters: Best Practices to Ensure Your Emails Get Opened

Struggling with low open rates? Learn the best practices to avoid spam filters and land your emails in the inbox in 2025.

Your Emails Won’t Get Opened If They Land in Spam

No matter how clever your subject line or compelling your content—if your email goes to the spam folder, it's game over.

In 2025, email service providers (ESPs) are smarter and stricter than ever. Their filters are built to protect users from unwanted emails, but they can also catch legitimate messages—unless you know how to avoid the traps.

This article will help you understand how spam filters work and give you practical tips to stay in the inbox. We’ll also explore how tools like SenderWiz help you build smarter, spam-free email campaigns.

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Why Emails Get Marked as Spam

Spam filters analyze:

• Sender reputation

• IP/domain blacklists

• Email content

• Engagement metrics (opens, replies, spam complaints)

• Technical setup (authentication, headers)

📉 Poor email hygiene or high bounce rates can instantly tank your inbox placement.

Let’s go through the key tactics to stay on the safe side.

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1. Authenticate Your Email Domain

Set up:

• ✅ SPF (Sender Policy Framework)

• ✅ DKIM (DomainKeys Identified Mail)

• ✅ DMARC (Domain-based Message Authentication, Reporting & Conformance)

These tell inbox providers, “I’m legit.”

💡 SenderWiz helps verify and guide your SPF/DKIM/DMARC setup with built-in domain management tools.

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2. Avoid Spammy Words and Formatting

Spam filters scan for common red flags like:

• “Buy now”

• “Limited time offer!!!”

• “FREE $$$”

• ALL CAPS or excessive punctuation!!!!

✅ Keep your subject line and body copy clean, clear, and natural. Use persuasive language—but avoid sounding like a scam.

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3. Use a Clean, Consistent “From” Name

Best practices:

• Use a real sender name (e.g., “Maya from SenderWiz”)

• Match your sender email to your domain

• Avoid generic names like “marketing@” or “noreply@”

⚠️ Frequent sender changes confuse filters and readers—stay consistent.

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4. Send From a Reputable IP and Domain

If you're using your own email server:

• Warm up your IP slowly

• Rotate sending across clean IPs

• Monitor your domain reputation using tools like Google Postmaster or Talos Intelligence

🔁 SenderWiz’s SenderAI can rotate IPs and domains automatically and replace blacklisted ones in real time.

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5. Clean Your Email List Regularly

Remove:

• Invalid emails

• Hard bounces

• Inactive users (90+ days of no engagement)

📭 A high bounce rate = major red flag to ESPs.

With SenderWiz, you can integrate with your verification tools or auto-remove bounces and unengaged contacts after each campaign.

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6. Use a Good Text-to-Image Ratio

Avoid:

• Image-only emails (spam filters can’t read images)

• One giant graphic as your entire message

✅ Use 80% text, 20% images ✅ Add alt text to all visuals

🖼️ SenderWiz helps you preview emails with and without images to ensure accessibility and deliverability.

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7. Avoid Excessive Links and Untrusted Domains

• Limit to 1–3 links per email

• Don’t use shortened URLs like bit.ly or tinyurl

• Only link to secure (HTTPS) and verified domains

🔗 Tip: Add one clear CTA—don’t flood the message with clickable distractions.

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8. Respect Unsubscribe Laws and Include a Footer

• Include a clear unsubscribe link

• Display your sender address

• Comply with GDPR, CAN-SPAM, and regional email regulations

📬 SenderWiz auto-generates compliant footers in every template—keeping you protected.

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9. Warm Up New Domains Slowly

If you’ve just launched a new sending domain:

• Start with small, high-quality lists

• Slowly increase volume over 2–4 weeks

• Prioritize engagement (opens, clicks, replies)

🔥 SenderWiz includes automated warm-up sequences to build reputation safely and gradually.

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10. Monitor Your Inbox Placement

You might have a high delivery rate—but are you landing in the Primary, Promotions, or Spam folder?

Track:

• Open rate drops

• Sudden bounce spikes

• Domain reputation tools (like MXToolbox, GlockApps)

🧠 SenderWiz provides inbox placement tracking and alerts you of potential reputation issues before they affect your results.

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Final Thought: Getting Opened Starts With Getting Delivered

Open rates start after your email makes it to the inbox—not before.

Following best practices, warming your domain, avoiding spammy language, and maintaining clean lists all ensure that your emails get seen, read, and clicked.

With SenderWiz, you don’t need to guess. Our built-in deliverability tools, smart rotation, domain/IP monitoring, and compliance features help you stay out of spam—and in front of your audience.

🛡️ Want to land in the inbox every time? SenderWiz gives you the tools to do it right.

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