Workflow

How to Optimize Images for Email (Avoid Blocking)

Published: 2026-02-01
Read Time: 4 minutes

Introduction

Email images often fail due to size, format, or spam filters. This guide helps improve deliverability.

Common issues

  • Attachments exceed provider size limits.
  • Modern formats are not previewed by some clients.
  • Too many heavy images trigger spam risk.

Optimization checklist

  • Keep single image around or below 200KB when possible.
  • Prefer JPG or PNG for compatibility.
  • Keep image count reasonable.
  • Use cloud links for many high-resolution images.

Recommended dimensions

PlacementSizeFile size
Email banner600 x 20050-100KB
Embedded product image300 x 30030-50KB
Attachment product image800 x 800100-150KB
Signature logo150 x 5010-20KB