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.
Understand the simple qualities of the Planets, for from thence thou shalt know all their mixt significations. - William Lilly (1602.-1681.)