Service not available, closing transmission channel. The server response was: 4.4.2 Message submission rate for this client has exceeded the configured limit
Error: Service not available, closing transmission channel. The server response was: 4.4.2 Message submission rate for this client has exceeded the configured limit Solution: Increase the default message rate limit (it was 5 on my case) Set-ReceiveConnector -Identity " EXCHANGE_NAME \Client Proxy EX01" - MessageRateLimit 200