I read on Sistanis page it says about touching non mahram women: «It is not permissible to touch the body of a non-mahram woman at all, except when necessary.» In what case would it be necessary? Is it allowed first time when meeting someone if the other part is the one initiating the handshake, and not me? For example when meeting new people or on interviews its pretty common to shake hands in western countries. Is this permissable as it would kind of seem rude if I had to just tell them I couldnt shake their hands. They might take it the wrong way. Later on I would usually just explain to them that I cant really touch them at all, if I were to meet them again, but is it haram for me to shake their hands the first time?

“When necessary” means like a medical necessity. As for the handshake, be creative and do your best to avoid it. Before they extend their hands, put your hand on your chest and greet them. And tell them I greet from my heart (and these days with COVID it’s easier to avoid the handshake).

Also you may see this clip:


If you were in a position where you felt embarrassed to the point that you cannot handle the embarrassment, then due to the Law of No Difficulty you can shake their hands.