You can use images in your Crossware Email Signatures such as company logos, staff photos, banners and social media icons. To ensure these display correctly across different email clients, it is important to use the correct image format, size, and hosting method.
Supported Image Formats
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PNG – Best for logos and icons. Supports transparency and sharp edges.
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JPG/JPEG – Best for photos and complex images. Smaller file size but no transparency.
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GIF – Only for simple graphics. Avoid animations as they are often blocked.
File Size and Dimensions
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Recommended maximum file size: 40KB per image
(Large files slow down email loading and may be blocked by some mail clients.) -
Recommended dimensions:
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Logos: around 200–300px wide
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Banners: 600px wide maximum (to fit standard email width)
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Icons: 24–48px square
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Resolution: 72 dpi is sufficient for on-screen display. Higher resolutions only increase file size without improving quality in emails.
Large files may be stripped, blocked, or slow to load in recipient's inboxes.
Best Practice Tips
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Optimise images before uploading.
Use tools like Photoshop, Illustrator, GIMP, or online compressors to reduce file size. -
Resize images to the exact size you want.
Avoid relying solely on HTML scaling. some clients (e.g., Apple Mail) ignore width/height attributes. -
Use PNG for logos with transparency.
This ensures a clean look on both light and dark backgrounds. -
Test your signature across multiple mail clients.
Check rendering in Outlook Desktop, Outlook Web, Apple Mail, Gmail, and mobile clients. -
Keep designs simple and clean.
Avoid oversized banners, heavy graphics, or unnecessary decorative images.