Email advanced settings missing

In Android 2.2 on my Motorola phone, I can use advanced settings to set me email address different that the account email settings. I cannot find a way to do this using the default email client in my Nexus 7 running Jelly Bean. HELP

The reason I need this is that I forward my personal domain email (at happyones.com) to my gmail account (at gmail.com) and I want my email to appear to come from my personal domain email address. I was able to do this on the iPad, in Thunderbird on my Win7 system and also on my cell phone running Froyo.

If there is no solution for the Nexus 7? Can I replace the default email app on the Nexus 7 by another more powerful client?