Conversations – When you send or receive email in Gmail all replies are connected to each other as a conversation. This provides the prior context for every email conversation. Before Gmail, if I couldn’t remember exactly what had been said in a past email, I’d have to go search through my old email folders and try to piece together the conversation. With Gmail, every part of the conversation thread is connected to the original email for easy reference.
Whenever I talk to people about their favorite Gmail features, threaded conversations are always at the top of their list. They make Gmail far more efficient than its desktop predecessors. I find it especially helpful when someone responds to a very old email. It’s so hard to remember an original email weeks or months after I’ve sent it. But when I see exactly what I had sent in the conversation thread, replying is much easier.