MailStone Gmail Extension

Certify your emails on the blockchain directly from Gmail — in one click.

MailStone for Gmail lets you send two kinds of legally useful email without leaving Gmail: the Opposable Mail, a certified email with its evidence file, and the Electronic Registered Delivery (ERD), the electronic equivalent of a registered letter. TWO PRODUCTS, ONE BUTTON Click the MailStone button in the compose window and choose: • Opposable Mail — your message reaches its recipients as usual; MailStone timestamps it, anchors it on the blockchain and keeps an evidence file of what you sent, to whom and when. • Electronic Registered Delivery — your recipient is identified, then accepts or refuses the delivery; every step is timestamped and gathered in an evidence file, enforceable under eIDAS. HOW IT WORKS Opposable Mail 1. Compose an email in Gmail 2. Click MailStone, choose Opposable Mail and pick a MailStone folder 3. The extension adds the folder's address in Bcc 4. Send: your evidence file is built on MailStone servers Electronic Registered Delivery 1. Compose an email and add your recipients in the To field 2. Click MailStone and choose Electronic Registered Delivery 3. Send as usual: a notification confirms that your delivery was taken into account 4. Follow its status (delivered, accepted, refused) from your MailStone space WHY USE IT ✔ eIDAS-qualified timestamping and blockchain anchoring ✔ Up to 50 recipients in one registered delivery ✔ Your plan usage and registered-delivery credits shown in the extension ✔ Everything happens in Gmail: no copy-paste, no extra tool PRIVACY The extension never reads or stores the body of your emails. It keeps your MailStone account address and session in the browser to call the MailStone API. For a registered delivery, it reads the recipients of the message you are composing to prepare the delivery; Cc and Bcc recipients are flagged as not covered. Nothing is shared with third parties. Full policy: https://www.mailstone.io/terms