It’s unlawful. The proof for the judgment that a man’s handshake with a marriageable female (ajnabiyyah) from her age of desirability, is Islamically unlawful is the Hadith of The Prophet, salallallahu ^alayhi wa sallam, he said, “If Allah  willed to punish the man who sinfully  touches a marriageable woman, his punishment would be more severe than to be stricken on his head with an iron bar. ” (Related by Al-Daraqutniyy. The … متابعة قراءة 30- What’s The Judgment On The Man’s Handshake To A Marriageable Woman?