After you deploy the Zivver OWA add-in in the Microsoft 365 admin center, the add-in shows and opens normally. Sending or discarding the unencrypted placeholder message does not work for any user, and no error shows. Or the add-in first works, but now and then a message never reaches the recipient. The sender sees no error and the message appeared to send normally.

Warning

Does a message not arrive and does the sender not see an error? The sender does not know the message was lost. Fix the cause on this page as soon as possible.

Cause

Deploying the add-in manifest is not enough. Two more setup steps are required:

• Admin consent for the Microsoft Graph API permissions.
• The Exchange Online mail flow rule zivver-action: discard. This rule deletes the temporary unencrypted placeholder message that the add-in sends next to the real secured message.

If you skip one of these steps, the add-in still loads, but core functions fail without a clear error.

The mail flow rule can also fail even when it exists. If another mail flow rule in your organization processes or discards messages before the Zivver rule runs, the placeholder message can be blocked silently. In some configurations the real message is blocked too. This happens when the other rule has a higher priority or is earlier in the rule order.

Solution

1. Check the admin consent:
   1. Log in to the Microsoft Entra admin center.
   2. Go to Enterprise applications and select Zivver OWA V6.
   3. Open Permissions and check that admin consent is granted.
      Is there no Zivver OWA V6 application, or is consent missing? Follow the steps in Give admin consent to the required Graph API permissions.
2. Check the mail flow rule:
   1. Log in to the Exchange admin center.
   2. Click Mail flow in the left pane.
   3. Select the Rules tab.
   4. Check that the rule zivver-action: discard exists and is enabled.
      Is the rule missing? Follow the steps in Create an Exchange rule for Zivver messages.
3. Set the priority of the zivver-action: discard rule to 0.
   The rule now runs before all other mail flow rules.
4. Check the other mail flow rules that act on message headers, the subject, or attachments. Check that none of them run before the Zivver rule or intercept the messages that the Zivver rule matches.
5. Send a test message with Zivver.
6. Check that the recipient receives only the secure notification.
   The recipient does not receive a placeholder message, and the message is not missing.

Tip

It may take up to 24 hours for changes to mail flow rules to take effect in Exchange Online.

Still need help?

If functions still fail, or messages keep going missing after you confirmed the rule order, contact Zivver Support and include this information in your request:

• The message trace ID of a message that did not arrive. See Message trace in the new Exchange admin center on how to find it.
• Is admin consent granted for Zivver OWA V6?
• Does the rule zivver-action: discard exist, is it enabled, and what is its priority?
• Which other mail flow rules act on headers, the subject, or attachments, and what is their priority?
• Which steps from this page did you try, and what was the result?