Malachi in Fausset's Bible Dictionary

("messenger of Jah"), or Jehovah; contracted for Malachijah, as Abi for Abijah (2 Kings 18:2; compare 2 Chronicles 29:1). The name is that of an office rather than of a person; it occurs in the sense "My (Jehovah's) messenger" (Malachi 3:1, compare Haggai 1:13). Malachi was Jehovah's last inspired messenger of Old Testament, announcing the advent of the great Messenger of New Testament; the transition link between the two dispensations, "the skirt and boundary of Christianity," to which is due his abrupt earnestness. Not identical with Ezra, as Chaldee paraphrase represents, for Malachi is never called a scribe, always a prophet, but Ezra always a scribe, never a prophet. The analogy of the headings of the other prophets favors the view that Malachi is a proper name. He supported or followed up the governor Nehemiah in the restoration of the national polity civil and religious, as Haggai and Zechariah previously had supported Joshua the high priest and Zerubbabel the civil governor in building the temple, Malachi (Zechariah 1:10; Zechariah 3:1-10) presupposes the temple already built. Like Nehemiah (Nehemiah 13:5; Nehemiah 13:15-22; Nehemiah 13:23-30) he censures the secular and mercenary spirit of the priests (Malachi 1:10; Malachi 2:14- 16; Malachi 3:8-10); the people's marriages with foreigners; the non-payment of the tithes (Nehemiah states the cause, the high priest's alliance with Tobiah the Ammonite and Sanballat); and the rich men's want of sympathy toward the poor. Nehemiah (Nehemiah 6:7) implies that "prophets" supported him, by his desire, in his reformation...

Link: https://bible-history.com/faussets/M/Malachi/