Beyond the pale
Unacceptable; outside agreed standards of decency.
Firstly, let's get the spelling clear here. It's 'beyond the pale', and certainly not 'beyond the pail' - the phrase has nothing to do with buckets. The everyday use of the word 'pale' is as an adjective meaning whitish and light in colour (used to that effect by Procol Harum and in countless paint adverts). This 'pale' is the noun meaning 'a stake or pointed piece of wood', a meaning now virtually obsolete except as used in this phrase, but still in use in the associated words 'paling' (as in paling fence) and 'impale' (as in Dracula movies).
The paling fence is significant as the term 'pale' came to mean the area enclosed by such a fence and later just figuratively 'the area that is enclosed and safe'. So to be 'beyond the pale' was to be outside the area accepted as 'home'.
Catherine the Great created the Pale of Settlement in Russia in 1791. This was the name given to the western border region of the country, in which Jews were allowed to live. The motivation behind this was to restrict trade between Jews and native Russians. Some Jews were allowed to live, as a concession, 'beyond the pale'.
Pales were enforced in various other European countries for similar political reasons, notably in Ireland (the Pale of Dublin) and France (the Pale of Calais, which was formed as early as 1360).
The phrase itself originated later than that. The first printed reference comes from 1657 in John Harington's lyric poem The History of Polindor and Flostella. In that work, the character Ortheris withdraws with his beloved to a country lodge for 'quiet, calm and ease', but they later venture further:
"Both Dove-like roved forth beyond the pale to planted Myrtle-walk".
Such recklessness rarely meets with a good end in 17th century verse and before long the lovers are attacked by armed men with 'many a dire killing thrust'. The message is clear - 'if there is a pale, decent people stay inside it', which conveys exactly the figurative meaning of the phrase as it is used today.