Shaking hands after Fardh Salah

Allamah Shaami (RA) states, 'To practise Musafaha after discharging Salaat is Makrooh (detestable) in all conditions since the Sahaaba (companions) had not engaged in this practice after Salaat and also due to this being a custom of the Rawaafidh (Shi'ah). Furthermore, it is narrated from Allaamah ibn Hajr (RA) of the Shaaf'ee Madhab that this is a detestable Bid'at (innovation) without basis in the Shari'ah. Musafahah in the Shari'ah is only when a Muslim meets his (Muslim) brother. (Fataawa Mahmoodiyyah, vol.1 pg.231; Mahmoodiyah)