Originally Posted by Dovster
I don't know of any Customs or Immigration proceedings on the way out of the US -- but perhaps there are different rules for non-citizens.
He's passing thru both both ways, but all of the boarding areas at Atlanta are in a domestic area. He has to pass thru customs to get there.
My only caveat would be busy holiday travel days -- Dec. 24 & 26 -- otherwise an hour & 55 minutes should be plenty of time.