My team Received always NDR message (ESMTP #554 Transaction Failed Spam Message not queued. ##) when they send for some domain and i tried to telnet the domain but i received the error : 421 4.3.2 Service not available, closing transmission channel
i have exchange 2007 sp3
please any solution for this problem
The 421 error could mean a problem on their side, or could just mean a firewall that does not like the telnet test trick but would accept communication from your server, or could be a consequence of being
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