- Connect to the Exchange Admin Center>Mail Flow>Receive Connectors>Add.
- Give the connector a name. For example, Cartegraph receive connector.
- Select Frontend Transport>Custom>Next.
- Either accept the default of TCP Port 25 (SMTP)>Next.
The port selected must be accessible from the Internet.
If security is a concern, you can change the default port to another unused TCP Port.
- Remove the 0.0.0.0-255.255.255.255 range. This must be done so that you do not become an open relay for anyone.
- Add in the IP address of the host from which you want to allow relaying, Cartegraph hostedenvironment ip address, 188.8.131.52)>Save.
- Open the properties of the connector you just created>Security>Under Authentication.
- Select Externally Secured (for example with IPSEC).
- Under Permission groups, select Exchangeservers and Anonymous users>Save.
- If you test and get the following error “421 4.4.1 Connection timed out” change some of the parameters of the receive connector.
- Execute the following PowerShell command:
Get-ReceiveConnector –Identity “Name of connector from Step 2” “ Set-ReceiveConnector –TarpInterval 00:00:00 –ConnectionTimeout
00:30:00 –ConnectionInactivityTimeout 00:20:00 –MaxAcknowledgementDelay 00:00:00 –MaxInboundConnection 10000
–MaxInboundConnectionPercentagePerSource 100 –MaxInboundConnectionPerSource unlimited
- Restart the Microsoft Exchange Transport Service on the Exchange server from PowerShell, Restart-Service MSExchangeTransport.
- Test the relay.