When you upload an image into an editor, it keeps its original file size. You can manually resize it after uploading, but that resizing just adds a style tag in the backend code. The problem is, many email programs—especially when replying—can strip out that style code, causing your image to display at its full, original size again. This issue is common across various editors, including the signature editors built into email programs.
To avoid the headache, it’s best to resize the image before uploading. That way, the correct dimensions are baked into the file itself, and you’re not relying on the email program to keep your in-editor adjustments.
Easily resize your image here: http://imageresizer.com
Suggested sizes:
- Banner-style image: 700–1024px wide
- Logo image: 200–300px wide