To me it seems logical that, when replying to an email, one would sign it again. In other words: That ones signature would again appear under one's reply.

However, currently, when replying to emails in a conversation, signatures are not added again and one is left to type it manually or copy-paste it. Or let go it altogether.

Maybe it's a cultural thing, but to me it seems unprofessional.

I do not enjoy this as this means that handy information in my signature has to be dug up from previous emails, which requires searching on the other party's behalf.

I would like for it to be possible to have signatures added to the bottom of each new reply, above the original email one is replying to. Below the type cursor, above the quoted email.