I know there is a plan in the works to allow clients to customize the "bounce@infusionmail.com" sender.
However, that's exactly what it is -- your e-mail is sent from "infusionmail.com" on behalf of you.
I recall there was a healthy debate around this topic.
You can read that here ... That said, get out and vote on the Infusionsoft Ideas site. Get your voice heard and suggest an alternative that helps you and your business. Our product management team places priority on upcoming new features and refinements based on what our clients feel is important.
To vote and comment on the Bounce matter, please go here:
http://ideas.infusionsoft.com/pages/general/suggestions/34365-stop-adding-sender-bounce-infusionmail-comThanks,
Joe