Hexagonal MnSb is a ferromagnet with Curie temperature and saturation magnetization values of 587 K and 110 emu/g, respectively. In this paper, the origin of the complex magnetic behavior of a single phase MnFe0.20Sb prepared using solid-state reaction method is examined. A thorough investigation of temperature dependent magnetization and magnetic relaxation measurements reveals the presence of a glassy like phase below 15 K. AC susceptibility measurements revealed the existence of a cluster glass-like state with a freezing temperature of 18 K. The presence of competing magnetic interactions and random occupation of Fe atoms at 2d site leads the system to exhibit a cluster glass state. Furthermore, resistivity measurements indicate that the material exhibits a Kondo-like behavior below 30 K and can be attributed to the interaction of conduction electrons with localized Mn moments.