Queens Gambit accepted...Be6 HELP

Cutious if anyone knows a standard continuation for:

1.d4 d5

2.c4 dxc4

3.e3 Be6

I like the Queens Gambit and have read that any attempt to back up the "extra" black pawn leads to serious structural weaknesses. Saw this 3...Be6 move for the first time in a blitz game and wasnt sure how to respond.

Would really appreciate any input from more experienced players 

I looked at this from  a black perspective a few weeks ago. Black puts his bishop on d5 and wants time to get his qside pawn roller going with c6 and b5. White seems to angle for e4, and in some lines , bearing in mind black is a pawn up, will sac bishop after trapped by e4 and have a very nice looking qside initiative for -1 in material.

I think Tony Miles tried it several times,.. the idea is to make White Work (thereby forcing him to use time / tempos) to regain the pawn.  The move is as good as you are,... if your a decent player it will give you a decent game, if not,...

An instant 4. Na3 seems to be OK; from c4 the knight could go to e5 where it might exchange with a knight on c6 or something. What would black's best response against this be?

To me, this Be6 line, intentionally blocking the e-pawn and hindering his own development, practically begs white to continue with Nc3, treat it as a true gambit, and develop as fast as possible.

Is this the only line in which the Queens Gambit is a "true" gambit? It seem that the consensus is that it is at least playable for black and doesnt lead to a structural collapse. REALLY appreciate the thoughtful comments guys