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

Contact your admin if you need help. Support options are available to admins who can sign in to the Microsoft 365 admin center with their admin account to contact support on behalf of users in their organization.

Don't forget to include your license ID or agreement number, your contact phone number & email address so we can contact you. If you already have a volume licensing support case number, you may be in a location where you can phone the Volume Licensing support team.

Learn how to install Office 2021, 2019, or 2016 on your PC or Mac.

Product key, purchase, and installing older versions of Microsoft 365: Install questions or errors during install Help with specific applications, and help for Microsoft 365 admins: Contact Microsoft

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 ...

Learn how to activate Office that is pre-installed on new Windows 10 PCs or using a new product key.

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.

If you're a user at a business and you're getting errors, contact the person who manages your business's internal website. These types of problems can often only be fixed by the webmaster (SharePoint admin) or someone at your company.

Send S/MIME or Microsoft Purview encrypted emails in Outlook using a work or school account with a qualified Microsoft 365 subscription.