Email marketing success depends on deliverability—whether your emails land in inboxes or get flagged as spam. One overlooked factor that affects spam filtering is email size.
Spam filters evaluate large emails as potential risks. If your email exceeds 100 KB, it may get clipped, delayed, or even blocked—especially on services like Gmail, Outlook, and Yahoo.
The Ideal Email Size for Deliverability
For maximum reach, keep your email size between 15 KB and 100 KB.
- Under 100 KB → Higher inbox placement
- Over 100 KB → Higher spam risk, possible clipping (especially in Gmail)
- Over 110 KB → Increased chance of blocking
Focus on Essential Content
- Keep emails short and concise—avoid long paragraphs.
- Prioritize important information upfront to keep users engaged.
- Use bullet points or numbered lists for easy reading.
- Limit excessive formatting (bold, colors, large fonts).
💡 Tip: If your message is long, consider breaking it into multiple emails instead of sending one large email.
Optimize Images for Faster Load Times
Heavy images slow down emails and increase spam risk. Follow these best practices:
- Use compressed images to reduce file size without losing quality (use tools like TinyPNG).
- Limit the number of images—use only essential visuals.
- Use image links instead of attachments (attachments increase email size and spam risk).
- Ensure images are responsive—they should load properly on mobile devices.
🚫 Avoid image-only emails—always include a good balance of text and images (ideally, a 60/40 text-to-image ratio).
Avoid Attachments – Use Links Instead
Instead of attaching PDFs, videos, or documents, upload them online and share a clickable link. This reduces email size and improves deliverability.
Where to host your content:
- Google Drive or Dropbox for documents
- YouTube or Vimeo for videos
- Your website or landing page for detailed information
💡 Tip: A well-placed CTA button (like “Download Now”) can improve click-through rates while keeping emails lightweight.
Test Before Sending
Before sending out your email, test it across different devices and inboxes.
- Send a test email to yourself (Gmail, Outlook, Yahoo, etc.).
- Check email size before sending.
- Make sure all images and links load properly.
- Use email testing tools like Litmus or Email on Acid to check spam scores.
💡 Tip: If Gmail clips your email, it means it’s too big. Try reducing image size or simplifying the content.
Key Takeaways:
The smaller your email, the better its chances of reaching your audience without spam issues.
- Keep emails under 100 KB to avoid spam filters.
- Optimize images and content for faster load times.
- Use links instead of attachments to reduce file size.
- Test emails before sending to check deliverability.
By following these best practices, you can improve inbox placement, increase open rates, and boost engagement for your Adflipr-powered email campaigns. 🚀
