Digital signing and encryption settings

Certificate

Select the certificate that you want for digital signing.

Before you click Choose a Certificate on the Certificate pop-up menu, you must first have a certificate added to the keychain on your computer. For information about how to request a digital certificate from a certification authority, see Mac Help.

Signing algorithm

A method for helping protect the integrity of a digital signature. Outlook can create a digital signature with any of the following algorithms: SHA-512, SHA-384, SHA-256, and SHA-1. Of these four algorithms, SHA-1 is the most compatible with other S/MIME applications, and SHA-512 is the most secure.

Sign outgoing messages

Select this option if you want to digitally sign all outgoing messages by default.

Send digitally signed messages as clear text

Select this option if you want the contents of the message to be readable for all recipients. This includes recipients without an S/MIME mail application. A recipient without an S/MIME mail application can read a clear text message but can't verify the digital signature.

Include my certificates in signed messages

Select this option if you want your recipients to be able to send encrypted messages to you.

Certificate

Choose the certificate that you want other people to use to send encrypted messages to you. Outlook also uses your encryption certificate for encrypted messages that are stored in your Sent Items and Drafts folders.

Before you click Choose a Certificate on the Certificate pop-up menu, you must first have a certificate added to the keychain on your computer. For information about how to request a digital certificate from a certification authority, see Mac Help.

Encryption algorithm

A method for encrypting a message and its attachments. Outlook can encrypt messages with any of the following algorithms: AES-256, AES-192, AES-128, and 3DES. Of these four algorithms, 3DES is the most compatible with other S/MIME applications, and AES-256 is the most secure.

Encrypt outgoing messages

Select this option if you want to encrypt all outgoing messages by default.

Client certificate

Choose the certificate that you want for certificate authentication.

Before you click Choose a Certificate on the Certificate menu, you must first have a certificate added to the keychain on your computer. For information about how to request a digital certificate from a certification authority, see Mac Help.