Green’s Dictionary of Slang

1. the buttocks [= tail n. (1)].

1984

Partridge DSUE (8th edn) 287: Buttocks (tail): ‘He fell on his Daily Mail’.

2. a tale; thus a lie.

1943		J. Phelan Letters from the Big House 144: Ole Rots don’t slip no Daily Mail.
1960		J. Franklyn Dict. of Rhy. Sl.
1977		D. Powis Signs of Crime 180: Daily Mail (newspaper) [...] tale, ‘He spun me a Daily (Mail) I just couldn’t believe.’.

3. ale.

1960

J. Franklyn Dict. of Rhy. Sl.

4. bail.

1959		J. Gosling Ghost Squad 24: Thieves’ argot, spoken properly, is a foreign language which needs to be learned [...] Among the words and phrases derived from rhyming slang are: [...] ‘What about Daily?’ equals ‘What about Daily Mail?’ (bail).
1977		D. Powis Signs of Crime 180: Daily Mail (newspaper) [...] bail, ‘Guvnor, what’s the chances of the old Daily Mail ?’.

5. sexual enthusiasm [= tail n. (7)].

1977

D. Powis Signs of Crime 180: Daily Mail (newspaper) [...] sexual proclivity, e.g., ‘She’s Daily Mail all right’ (she is accommodating in the sexual sense).