Connected to 172.16.2.14 (172.16.2.14).
Escape character is '^]'.
421 4.3.2 The maximum number of concurrent connections has exceeded a limit, closing transmission channel
Connection closed by foreign host.
For Exchange 2016 you may need to run this command first
Get-ReceiveConnector -Identity <connectorname> | fl MaxInboundConnectionPerSource
You can also reference the following Microsoft documentation