You have already added include:spf.exclaimer.net to your SPF record as described in this article, but your emails are consistently not being delivered and you receive an NDR.
Your Send and Receive connectors may not be configured correctly in Office 365, causing mail to retain internal Exchange email headers.
To fix this issue, follow the steps below:
- Remove the Office 365 connectors and Transport Rule associated with Signatures for Office 365.
- Log into the Exclaimer Cloud portal and click the Settings button, from the options list in the top right of your screen:
The Settings page is displayed:
- Select the Mail Flow tab:
Mail Flow options are displayed:
- Click the Setup button associated with Office 365 Connector Setup. The Office 365 Connector Setup wizard is launched:
- Click Next. You are prompted to enter credentials for a Global Administrator:
- Enter credentials for your Global or Exchange administrator account and click Next.
- Choose which emails should be routed to Exclaimer Cloud for signature processing, before being sent back to Office 365 for delivery:
Here, you can choose to process emails for everyone, or only for users in a specific group.
- Having made your selection, click Next and the setup will begin:
- When the wizard is complete, confirmation is displayed:
- Click Close to exit the window.
- Send a test email with the same variables as the previously bounced email.
Note: Please be aware that any changes to a Transport Rule may take up to an hour to become operational. If you find that the email signature is not added to the test email, wait a short time and send it again.