In 1075 Malet was sheriff of Suffolk, and helped supress the rebellion of Ralph Wader. Afterwards, he appeared frequently at King William I's court. All changed with the accession of William II. By 1094 Malet's English lands had been taken away from him. The reasons are unknown, and no more is known of Malet's activities during William II's reign. Most likely he was in Normandy, and it may be that his falling out with William II was due to his preference for Duke Robert of Normandy in the rivaly between the two brothers.
Malet suddenly reappears three days after the death of William II in 1100, as a witness to Henry I's coronation charter. He must have been with Henry at the time of William's death, or rushed from Normandy when the word came. In any case, Malet soon regained his office as sheriff of Suffolk, and his honor of Eye. He was a close councilor of the king, and was appointed master chamberlain (probably the first to hold that office).
It used to be thought that Malet had some quarrel with the king, and again lost his lands, on the basis of some statements by Orderic Vitalis, but most historians now think Orderic confused Malet with his successor William. Instead it appears he remained in the king's confidence and held his lands until his death. He may have died at the battle of Tinchebrai, though no specific evidence supports this; he may in fact have lived on through 1107.