Convert S/MIME to ICO
Convert S/MIME to ICO online: the signed email laid out with its headers and body, saved as a 256 × 256 ICO icon. Free, no sign-up.
Drop your S/MIME files here
Up to 50MB per file.
Conversion Settings
Files are encrypted and auto-deleted after conversion
How to Convert
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Upload your S/MIME files
Drag and drop or select S/MIME files from your device. You can upload multiple files at once.
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Configure Output
Choose any available ICO output options, then start the conversion.
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Download ICO files
Once conversion finishes, download your files individually or as a compressed ZIP archive.
Why convert S/MIME to ICO?
S/MIME files hold an email secured with a digital signature or certificate, as sent by Outlook, Apple Mail and other clients that use S/MIME. The image shows the From, To, Cc, Subject and Date of the message, its body, and a list of attached parts by name and type.
ICO output is a 256 × 256 pixel Windows icon: the image is scaled to fit with its proportions kept, and the surrounding space is transparent.
Frequently Asked Questions
How do I convert S/MIME to ICO?
Drop your S/MIME file above and press Convert. Our servers read the signed message, lay out its headers and body, and render the page. The result is saved as a 256 × 256 ICO icon, ready to download.
Can a signed S/MIME email be converted to ICO without the sender's certificate?
Yes. The message is read as it was received, so its headers and body are laid out with no certificate or key needed.
Are the Cc recipients of an S/MIME email included in the ICO?
Yes. When the message was copied to others, a Cc row lists them beneath the From and To rows in the header table.
Which part of the S/MIME becomes the ICO icon?
The first page of the rendered content is used for the icon, fitted inside the 256 × 256 square with its proportions kept.
What size is the ICO made from a S/MIME file?
The icon is 256 × 256 pixels, the largest standard Windows icon size. The image is fitted inside the square with its proportions kept and a transparent surround, stored as a PNG-compressed icon.
Is my .smime file kept private?
Your file is uploaded over an encrypted connection, converted on our servers and deleted automatically within 24 hours. We never read, share or keep your files, and no account is needed.