To try the thousands of add-ons available here, download Mozilla Firefox, a fast, free way to surf the Web!Close
Welcome to Firefox Add-ons.
Choose from thousands of extra features and styles to make Firefox your own.Close
Gmail S/MIME 0.5.2.1-signed.1-signed Requires Restart
Send and receive signed and encrypted messages in Gmail.
About this Add-on
0.5.2 adds support for Firefox 5, Firefox 6, and the latest versions of SeaMonkey.
With the Gmail S/MIME extension, you can send and receive signed and encrypted S/MIME messages in Gmail. Secure your e-mail today, including your attachments! Version 0.5.2 inter-operates with every S/MIME-capable mail client including Microsoft Outlook (2000-2010), Microsoft Outlook Express, Mozilla Thunderbird, and Apple Mail.app, and now works up through Firefox 4.0, Seamonkey, and the latest versions of Gmail.
Please update Gmail S/MIME to 0.5.2 (June 21, 2011) for the latest updates and fixes.
Help on using this extension can be found at:
Please contact the developers directly if you have questions or problems. We do not monitor the comments on this website regularly.
If you want others to send you encrypted mail, you need a digital certificate. You can get a free one from Comodo at:
Just follow the prompts to have the certificate installed directly in your browser. Sending your certificate to others is as easy as clicking “Sign” on the toolbar. For more information, visit:
Always remember to look at the toolbar before sending a message, to see whether you are signing or encrypting it. By default, messages are not signed, but are automatically encrypted if you have digital certificates for all of the recipients.
Send us e-mail if you have additional questions or comments. Feel free to send us signed and encrypted e-mail, too. We can read them now. :-)
Fixed statusMessage detection.
Updated function signatures for disabling autosave in the latest version of Gmail.
This add-on is not compatible with your version of Firefox because of the following: