Lookup for "214 4.6.5"
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 (4.6.5)
Conversion Failed
A conversion was required but was unsuccessful. This may be useful as a permanent or persistent temporary notification.