Lookup for "214 4.4.2"
Temporary Error - This status code indicates a transient issue and may resolve itself.
Basic Status Code Details (214)
Help message [Information on how to use the receiver or the meaning of a particular non-standard command; this reply is useful only to the human user]
Enhanced Status Code Details (4.4.2)
Bad connection
The outbound connection was established, but was unable to complete the message transaction, either because of time-out, or inadequate connection quality. This is useful only as a persistent transient error.