I finally added my domain to my gmail account.. but no avatar! x.x

that smtp outgoing email is what screws up the avatar though, afaik that's something gmails outgoing servers do after it hits the server. you should still be able to setup the "reply to" portion to your domain to get the gmail output servers to do the work and fix the avatar the only downfall is inside the raw header of the email, the actual gmail address is revealed for those savvy enough to go looking into where the email came from. for most everyday users though, they'd never even know it had any association to google at all though.

edit: sorry for long run-on sentences and poor formatting.

sorry, it has been years since i looked at my settings now. it looks like it's now called "Send Mail As:" under the "Accounts and Import", inside the gmail settings. You can "Add another email" and "treat it as an alias" and then make it the default reply-to. xD

then just drop the smtp entirely and it will have the same effect with only that one mentioned drawback. ^^

edit: it does come with gains to balance that drawback too though, for instance people can find you on google/google+ with your domain email instead of only your gmail email. additionally you can login gmail with your domain email instead of your gmail/username. probably a few other things i can't even think of.