About digital signatures and certificates in Office, and buying a digital certificate from a certificate authority or create your own.

Two-step verification is an optional security feature that, by using two forms of identity—your password, and a contact method (also known as security info)—makes it harder for someone to break into your Microsoft account.

See how to view the details for signatures and certificates.

Certificate authority (CA) A certificate authority is an entity similar to a notary public. It issues digital certificates, signs certificates to verify their validity and tracks which certificates have been revoked or have expired. Top of Page Digital signature assurances The following terms and definitions show what assurances are provided by digital signatures. Authenticity The signer is ...

了解如何添加安全信息以便保护你的 Microsoft 帐户。

Select Edit contact, and then select Save & Close. View a certificate for a contact On the Navigation bar, select People. Select the person's name, and then on the Contact tab, select Certificates. Digitally sign a single message in classic Outlook In the message, on the Options tab, in the Encrypt group, select Sign.

了解如何新增安全性資訊以保護您的 Microsoft 帳戶。

For technical support, go to Contact Microsoft Support, enter your problem and select Get Help. If you still need help, select Contact Support to be routed to the best support option.

In this case, you'll need to choose another method or contact your organization's help desk for more assistance. Before you can register a security key, you must have at least one additional security verification method registered.

A phishing email is an email that appears legitimate but is actually an attempt to get your personal information or steal your money. Some deceptive emails appear to be from a safe sender but, in fact, have a "spoofed" source address to fool you. Here are some ways to deal with phishing and spoofing scams in Outlook.com. Spoof intelligence in Exchange Online Protection helps prevent phishing ...