The emails sent to Exclaimer Cloud are not being delivered (or delivery is delayed), and the Microsoft 365 message trace shows the following error:
You received this error message because the Exclaimer proxy server is unable to identify the server to which the message needs to pass.
Typically, this scenario occurs when the Mail Routing options in Exclaimer Cloud are configured to return messages to the Sender Domain. The configuration implies that Exclaimer Cloud performs a lookup for each processed email, passing the processed email back to the server(s) specified within the sending domain name’s MX records.
The steps described below are from the old UI.
Follow these steps to resolve the issue:
- Log into the Exclaimer portal (portal.exclaimer.com) and Launch your subscription.
- Click on the options list from the top-right of your screen and select Settings.
- The Settings window is displayed, select the Mail Flow tab.
- Click the Edit button under the Mail Routing.
- From the Mail routing mode drop-down, select Static Domain.
- In Domain name, enter the Microsoft 365 domain name (ending in .onmicrosoft.com).
NOTE: The MX record for the Domain name (in the Mail Routing settings) should specify a single Exchange Online Server for your Microsoft 365 tenancy.
To check the MX record for your own Domain name, use a DNS lookup tool, such as MX Toolbox.
- Click Save to save the changes.