Gmail Improves "Undo Send"
My favourite mail system is Yahoo, I have more than 20 folders and every day I check my Yahoo mail at least twice. Because it been long time I used Yahoo, still I prefer Yahoo, but I like Gmail too. One day I sent very important email on yahoo, as soon as I clicked send, I remember that I did not write anything for subject, sh..t, f..k. I became very angry. In Gmail, it is possible to undo sent mail, recently they improved so you can change setting and undo sent mail up to 30 seconds. read more here