The most football management rejection letters received is 105 by David Boyne (UK) of Bushey, UK, between 16 November 1994 and 2 November 2010. Boyne has received rejections from such prestigious clubs as Arsenal, Chelsea, Liverpool and the Irish and English national squads.
Boyne had four letters which he submitted disqualified for either not rejecting him or for stating that the position was not open (see end of "Docs 2" attached for four rejected rejections): Mansfield Town, Wales national side, Cambridge United, Southend United.
Please note: Comments below may relate to previous holders of this record.