Duxbury revealed the exchange during an interview with the 'Financial Times', joking that he receives texts from the former Watford owner on a daily basis.
The message in read: "Tom Heaton. I'd still buy him. [Ben] Foster's not consistent. Love, Elton."
It came in the immediate aftermath of Watford's thumping home 4-0 defeat at the hands of Bournemouth back on October 6.
The loss was Watford's third in four games following a fine start to the season as goals from David Brooks, Josh King (two) and Callum Wilson secured a comfortable victory for Eddie Howe's side.
John is considered akin to royalty at Vicarage Road, where he has a stand named after him, having owned Watford between 1976 and 1987 and again between 1997-2002.
An honourary Life President, Sir Elton's advice was politely declined on this occasion, though Duxbury was keen to stress that the message was sent in "a light-hearted way".