Xink rerouter accepts messages from Microsoft 365, adds a signature, and returns messages back to Microsoft 365 tenant. In cases that the message bounces back, it is suggested to add the Xink server IP to your third-party spam filter or firewall's whitelist. You can also modify the transport rule to add the server IP to the exception and/or add it to the tenant's allow list. Please refer below for the steps.
Excluding Xink server IP by modifying the transport rule
1. Identify the server from the smarthosts configured in the Xink-Auto-ReRouting-Out connector.
Ex. xink-rerouter-us.eastus.cloudapp.azure.com, indicated that the Data Center is in US.
Once identified, check the assigned IP for the specified Data Center.
Note: You may also check with Xink Support for the account's Data Center and IP.
2. Once you know the IP address, edit the transport rule for your third-party filter/firewall.
3. Add the exception "The sender is..." and select "IP address is in any of these ranges or exactly matches", then enter the identified IP address from the previous steps. 4. Save the changes made in the transport rule.
Adding server IP to the tenant allow list
1. Go to Protection in Exchange Admin Center.
2. Access Connection Filter tab.
3. Click edit button and go to Connection Filtering.
4. Click the "+" sign in the IP Allow list section and add the identified server IP.
Note: In New Exchange Admin Center, you can go to Other Features > Connection Filter.