The Stags have offered Boulding a new contract, but is unlikely to choose non-league football over a move to a League One or League Two side.
According to the Scunthorpe Telegraph, Boulding is on the Iron manager Nigel Adkin's summer shopping list.
Lincoln City and Grimsby Town have also made enquiries about Boulding, a former professional tennis player, and a move back to Blundell Park would be the much travelled strikers second spell in Grimsby.