Relevant Products: Exclaimer Cloud - Signatures for Office 365
When using Exclaimer Cloud in a hybrid environment using centralized mail flow, you may find that emails do not route to Exclaimer Cloud to have signatures applied and are routed on-premise instead.
Currently, the hybrid send connector is set to apply to all messages at the connector level and commonly appears similar to the following connector:
The objective of this solution is to modify the connector setup so that it uses a Transport Rule with a lower priority than the Exclaimer Transport Rule, therefore ensuring that signatures are applied before messages are routed on-premise.
Please follow the steps below to reconfigure the hybrid send connector (note that there may be downtime during the change - we recommend making this change out of hours where possible):
- Step 1: Reconfigure the hybrid send connector
- Step 2: Add a new mail flow rule
- Step 3: Configure the new mail flow rule
- Step 4: Add your .onmicrosoft address to the Exclaimer portal
Step 1: Reconfigure the hybrid send connector
1. Log on to the Office 365 Portal as a Global Administrator.
2. Open the admin center.
3. Click admin centers and select Exchange.
4. Select mail flow and then connectors.
5. Reconfigure the hybrid send connector to apply Only when I have a transport rule set up that redirects messages to this connector:
6. Leave all other connector settings as they are and save the connector.
Step 2: Add a new mail flow rule
1. Still in the admin center under mail flow, select rules.
2. Click the + (plus) button to add a new rule.
3. Give the rule a name - for example: Send on-premise.
Step 3: Configure the new mail flow rule
1. Scroll down and click the More options link to enable additional rule options.
2. Add a condition which states The sender is located inside the organisation. This ensures that all emails sent from your Office 365 tenancy are routed through the connector.
4. Add an action which states Redirect messages to the following connector and select your hybrid send connector. The rule should now resemble the example below:
5. Add an action using the options Modify the message properties and Set a Message header.
6. Set the message header to something such as 'x-sentonpremise' and then the Value to 'True'.
7. Add an exception for 'A Message Header' that 'Matches these text patterns' and set that rule to also be for the text 'x-sentonpremise' and the Value 'True'.
This combination of adding the header and setting it as an exception means that if the mail is returned to your 365, it is not then redirected to the connector again and prevents mail loops.
8. Save the new rule. It should now be shown in the rules list with a priority of 1. Also in this list, you should see an Exclaimer rule called Identify messages to send to Exclaimer Cloud, which has a priority of 0
Step 4: Amend the Exclaimer mail flow rule
1. Open the rule named Identify messages to send to Exclaimer Cloud.
2. Scroll down until you see the option to Stop processing more rules:
3. Select this option to force the Exclaimer rule to run and to prevent Office 365 from running the hybrid rule until the email is returned from Exclaimer Cloud with a signature attached. At this point, the Exclaimer Transport Rule will have its exception triggered by the Exclaimer message header once it returns, and the hybrid rule will be used instead.
4. Your Office 365 set up is now complete. Please allow up to one hour for mail flow changes to replicate in Office 365.
Step 5: Add your .onmicrosoft address to the Exclaimer portal
The final step of this process is to return to the Exclaimer Cloud portal to ensure emails are routed to Office 365 once the signature has been applied:
1. Log in to your Exclaimer portal.
2. Select Launch for your subscription
3. Select Settings in the Cloud portal
4. Select Mail Flow.
5. Under Mail Routing, select
6. Select Static domain.
7. Enter your .onmicrosoft address (listed in your Office 365 tenancy under Domain Name):
8. Save changes.
Your setup is now complete.
If you experience any problems, or if you would like to have someone from Exclaimer on the telephone or via a remote session during the setup process, please let us know or raise a support ticket here.