Error:
Could not deliver a message to the following recipient(s):
Failed Recipient: [email protected]
Reason: Remote host said: 601 Attempted to send the message to the following ip's:
x.x.x.x
Could not deliver message to the following recipient(s):
Solution:
601 errors are generally related to network issues.
The connection could have been interrupted in transit, the connection could have been dropped, or timeout out. The best way to test this is to run a telnet command from your server to the IP addresses that are in the 601 error and see if you get a 220 response.
If you do not this could be network-related or the IP address your telneting from may be blocked on the receiving end.
So you need to check the issue at the recipient end.