Green’s Dictionary of Slang

1. (Aus.) a rumour, a report, racing tip; information on crime.

1967		‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxvi 4/1: mail: Information of any sort.
1968		J. Alard He who Shoots Last 44: ‘Da vine sex he’s lookin’ hard fer ya.’ [...] ‘Thanks for the mail, Mouse.’.
1975		Bulletin (Sydney) 26 Apr. 44: One of the old rorters up the Cross tugged me coat a week ago. His mail was that if I didn’t weigh in soon I’d be gathered for sure, but, shit, I didn’t expect I’d get dished up like this just on a lousy dud.
1986		C. Bowles G’DAY 83: Woss the mail on the joker with the leather pants? Looks like a bit of a bumjumper ter me.
1993		M.B. ‘Chopper’ Read How to Shoot Friends 45: Police often let some good crooks run if they give them good mail.
1996		(con. 1950s) in P. Doyle Get Rich Quick (2004) 23: I’d like to get the mail on Jim Swain.
2012		(con. 1943) G.S. Manson Coorparoo Blues [ebook] [He] crept down to the camp and gave him the mail.

2. (US black teen) money [? like the US mail it ‘gets through anywhere’].

1983		Too $hort ‘Female Funk’ 🎵 I gotta get more, gotta get mail.
1992		Click ‘Life’ 🎵 Serious about my mail, don’t give a fuck about a jail cell.
1997–2000		College Sl. Research Project (Cal. State Poly. Uni., Pomona) 🌐 Mail (noun) Money.
2000		W. Shaw Westsiders 21: More words seem to be invented each week, faster than any Webster’s could keep track: ‘G’, ‘grip’, ‘bank’, ‘mail’ [...] It is the fecund vocabulary of desire.
2008		Big Pokey ‘The Way I Live’ 🎵 Trying to feed the fam and make some mail.
2012		Obie Trice ‘Petty’ 🎵 Well, that’s my female, shorty gets that mail.