If the automatic installation via the Control Panel does not work immediately, it is usually due to a temporary issue.
We recommend trying the automatic installation again at a later time. Please note that our add‑in is deployed through the standard M365 rollout process, and it may take up to 12 hours until the add‑in is installed for all users.
If the automatic installation is still not successful later on, you can also install the add‑in manually in your O365 tenant by following the steps below.
Note:
If the Outlook add‑in is currently still registered in your tenant, you must remove it before performing the manual installation. This can be done via the corresponding button in the Control Panel. Afterwards, you can proceed with the manual installation of the Outlook add‑in.
Removing via the Control Panel
- Navigate to Email Security > Spam & Malware Protection > Add‑Ins and Connectors.
- Under Outlook add‑in, click Remove.
- You will then need to log in with your Microsoft 365 administrator credentials and confirm the permissions.
Manual installation of the Outlook Add‑in
- Log in to the Exchange Admin Center via:
https://admin.cloud.microsoft/#/Settings/IntegratedApps - Under Deployed apps, click Upload custom apps.
- Select Office Add‑in as the app type and upload the manifest file using this link:
https://cp.hornetsecurity.com/outlook-addin-versions/4.9/web/manifest_v4.xml - After validation, you can select which users should see the add‑in.
- After completing the following steps, the add‑in will be deployed.
Please note: It may take Microsoft up to 48 hours to distribute the add‑in.