I use Gmail for my personal email, and as an archive for my EnGraph email, but haven’t been able to use it as my main email client as it appends a “On Behalf of” to messages sent from Gmail using a non-gmail address.
Google has recently released an update to Gmail allowing you to use an SMTP server of your choosing, which removes the “On Behalf Of”.
Now I can email my clients from Gmail and they don’t know the difference!