Function MQ_send
Send raw data directly to the SMTP connection.
MailerQ takes care of its own output buffering, so you can be sure that all data is always delivered, unless the connection is suddenly closed by the peer.
/**
* Send data over a TCP connection
* @param connection the connection in which the data was stored
* @param buffer data to size
* @param size size of the buffer
* @return size_t number of bytes sent
*/
size_t MQ_send(MQ_Connection *connection, const void *buffer, size_t size);