CAUTION: this is a non-blocking send. If the message cannot be sent, then
it will return with an error and errno set to eagain. If the send is
a limited fanout, then the returned status is the status of the last
CAUTION: this is a non-blocking send. If the message cannot be sent, then
it will return with an error and errno set to eagain. If the send is
a limited fanout, then the returned status is the status of the last