The regular practice of
shaking hands after finishing the obligatory Salah is a Bid`ah (an innovation in religion), whether it is done between the Imam and the Ma'mums (persons being led by him) or among the Ma'mums themselves. This act is baseless and should be abandoned, as the Prophet (peace be upon him) stated:
Anyone who does an action which is not stated in this matter of ours (Islam) will have it rejected.
Neither the Prophet (peace be upon him) nor any of the Rightly-guided Caliphs are reported to have practiced such a custom. The best line of conduct to follow is that of Muhammad (peace be upon him) and the worst of affairs are matters newly innovated in Islam, (Part No. 2; Page No. 195) as every novelty is an innovation, and every innovation is misguidance.May Allah grant us success. May peace and blessings of Allah be upon our Prophet Muhammad, his family and Companions.