When sending a new email, and for those that are snail-mail-esque I always sign.
But when it is a conversation that a chat should have been used for, especially at work, I am less doing it.
At work we have M365, so I am often also using the built in feature in Outlook to move the conversation to a Teams chat. Especially when more than two people are in it.
Email is requiring so much own time to manage, maintain and keep (archiving for future needs) on individual level = #badUX.