Malachi translates from Hebrew as "my messenger," a title rather than a personal name in its earliest biblical use, later adopted as a given name in its own right. It carries connotations of delivering something important -- a voice entrusted with a message rather than speaking only for itself.
The work done to obtain perfumes and to recite invocations is better than the work done with precipitable gases and other spirits. - Picatrix (Andalusia, ~1000.AD)