I've seen on Sayed Sistani's website that any kind of chatting with non mahrams is forbidden. The ruling seemed very strict and I don't understand how it's applicable to our mixed lives today, unless we are completely segregated which is unrealistic in most cases.

I understand that joking and these kinds of things are not allowed, but why are simple conversations/intsructions and intellectual discussions also forbidden?

Why is communication not allowed when boundaries are kept and in a formal setting?

How can one preform a task/job if such interactions are deemed sinful? Be it at a job, or an online forum/chat group

My question is primarily about online interactions. But an additional question, would the ruling change for in real life?

Please shed some light and guidance on this matter.

Simple, professional conversations are allowed. As long as one is not joking, flirting, or saying anything sensational, charming or sexual in nature then it’s permissible.

However, one must be careful, that’s because haram relationships and sins usually start from these “harmless” conversations. So as long as one is constantly vigilant and self-monitors everything he says, he can have appropriate conversations with the opposite gender.