My main email I've used and like is - email@example.com
I've added that to my Gmail account and made it also the "default" reply from address
There are many options in the Gmail Mail Settings panel and I'm not sure exactly what else I need to do now, and then what I have to change in my mail clients like Outlook to start making them all work nicely again
Thanks in advance
read this carefully. It should give you some idea about how to do it. Its an old article but still should be good.