Deploy MailGuard to Microsoft 365

Start here for a new organization

1. Open Get started and use the work or school account for the organization that will deploy MailGuard.
2. Complete the Microsoft sign-in and MailGuard activation for that same organization. Stop and contact support if Microsoft presents a personal account or the wrong organization; do not continue with a different account.
3. In the MailGuard dashboard, confirm the organization, then invite each person who should use MailGuard.

Microsoft sign-in establishes the organization path. It does not grant uninvited people access. An organization administrator must invite each person before that person’s first Outlook sign-in.

Administrator deployment steps

1. Sign in to the Microsoft 365 admin center with an account for the same organization that can deploy add-ins.
2. In the MailGuard dashboard, create a MailGuard invitation for each person who should sign in from Outlook. Invitation email and Microsoft UPN must match. A MailGuard invitation, a Microsoft 365 add-in assignment, and Outlook showing the add-in are three separate steps.
3. Go to Settings → Integrated apps.
4. Choose Upload custom apps (or Add-ins → Upload custom app, depending on your admin center layout).
5. Upload the Outlook add-in file from this page (MailGuard.outlook.xml).
6. Assign MailGuard to specific users or groups (for a single mailbox test, assign only that user).
7. Complete deployment. Microsoft propagation can take from a few minutes up to 24 hours. Wait out that window before troubleshooting, and do not upload the file again or change the assignment while you wait.

What a successful assignment looks like

In Microsoft 365 admin center, open Settings → Integrated apps → MailGuard. A successful assignment shows status OK, host product Outlook, and only the people who should see MailGuard. If that is already true, stop. Do not upload another copy and do not add another user to test the same mailbox.

Hosted add-in URL (alternative to file upload): https://guard.code13.ca/outlook-addin/manifest.xml

The longer administrator reference, including file checks when you need them, is the Microsoft 365 administrator runbook.

Where users find MailGuard after deployment

• Classic Outlook for Windows: Open a message and use MailGuard on the ribbon. If it is missing, open Get Add-ins, refresh Admin-managed, then restart Outlook. MailGuard has been used successfully here, including current production Microsoft sign-in and a Trusted verdict.
• New Outlook: Open a message, then Apps, then MailGuard. MailGuard has been used successfully in New Outlook.
• Outlook on the web: Open a message, then Apps, then MailGuard. MailGuard has been used successfully in Outlook on the web.
• Outlook for Mac: Open a message and use MailGuard. MailGuard has been used successfully in Outlook for Mac.
• Outlook mobile: Outlook mobile is separate from those results and is not yet a proven place to assign MailGuard.

After the add-in appears, people sign in with the work or school account invited for the organization.