I use emojis very sparingly, but I almost always include some sort of positive comment if I've had a long exchange or back and forth with someone, like an "Oh wow, thanks for bringing this to my attention" or an "I also had trouble with this at first" or a "If you need anything else let me know". I try to keep things conversational but still type well, because that's just what I've always done, in work and socially.