We have a newer team member that pointed this out to us. He mentioned in a team meeting that he sees us answering people on Slack or email after hours and wondered if he's expected to do the same. It's really best for everyone to just be off work when you're off work. I've started letting things sit til morning if it comes in after I'm out. I don't want to be the guy that makes another guy feel pressured to keep slack on his phone all night.