The digitally signed email is accompanied by a digital certificate containing the sender's public key information, and the public key can be used to send encrypted emails to the sender.

Select an email with a digital signature, click the Sender Information menu item in the Mail menu, and click the Add to Address Book button in the pop-up card properties dialog box to add the sender to the address. in the specified folder of the book. The card added will contain a digital certificate.

If you already have a card for this sender in your address book and just want to add the digital certificate to the original card, click Properties on the Mail menu, and then click Add on the Security tab. Go to the address book button, and the Check Certificate dialog box will pop up, listing all cards that match the email address of the certificate. Select the required card, click the OK button, and the digital certificate will be added to the selected card.

If you select Add sender's certificate to my address book in Tools | System Settings | Security Advanced Settings or select this check box, when you receive a digital certificate When signing an email, Foxmail will automatically add the sender's certificate information to the address book.