How to digitally sign an email

Mohd Arif 921 Reputation points

We have M365 subscription. To enhance mail security, we are planning to add a digital signature to mail. So anyone would send email, it will be digitally signed using user or computer certificate to claim the ID of sender that is from a genuine user, not an imposter. How can we do it? appreciate your help.

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  1. Vadims Podāns 8,866 Reputation points MVP
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  2. Aaron Xue-MSFT 2,581 Reputation points Microsoft Vendor

    Hi @Mohd Arif ,

    Agree with crypt32.

    You need to install the S/MIME before you sign the message.

    I have done some research, here’s an article for you reference.

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  3. Limitless Technology 39,331 Reputation points

    Hi there,

    -On the File tab, click Options >Trust Center.
    -Under Microsoft Outlook Trust Center, click Trust Center Settings.
    -On the Email Security tab, under Encrypted Mail, select the Add digital signature to outgoing messages check box.

    Here is a link for a detailed description of the process that you must follow.

    Secure messages by using a digital signature

    --If the reply is helpful, please Upvote and Accept it as an answer--

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