Lookup for "500 2.3.4"
This status code indicates a successful delivery or other operation. Any details are simply notes.
Basic Status Code Details (500)
Syntax error, command unrecognized [This may include errors such as command line too long]
Enhanced Status Code Details (2.3.4)
Message too big for system
The message is larger than per-message size limit. This limit may either be for physical or administrative reasons. This is useful only as a permanent error.