Lookup for "354 2.4.1"
This status code indicates a successful delivery or other operation. Any details are simply notes.
Basic Status Code Details (354)
Start mail input; end with
Enhanced Status Code Details (2.4.1)
No answer from host
The outbound connection attempt was not answered, because either the remote system was busy, or was unable to take a call. This is useful only as a persistent transient error.