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 are not configured correctly in Office 365, causing mail to retain internal Exchange email headers.
To fix this issue, do the following:
- 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 located in the top right of your screen:
- A separate lightbox will open. Navigate to the Office 365 Connector Setup section at the bottom and click 'Setup':
- Enter the credentials for your Global or Exchange administrator account, click 'Next' and follow the steps shown in the Wizard:
- When the Wizard is complete, send a test email with the same variables as the previously bounced email.
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.