I’m working on another version of the mailbox, as well as another shot for this one, so comments are more than welcome.
wow so nice lighting 
is this vray-sun sky system?
can u tell us about ur lighting?
So I am assuming thats all 3d … that is pretty damn cool
Huh, i didn’t mention what’s 3d and what’s not. Is it obvious?
Well I didnt read the subject properly and thought it was all 3d.. and in my eyes, really good 3d.
Now I see its a photon montage what ever is 3d fits in really well 
Nice job, the only thing that pops to my eyes is the shadows. The shadowed side of the mailbox is a lot more blueish then the shadowed part of that rail next to it.
Really nice job!
Regards,
Thorsten
sorry I didnot read topic name fine too
it is a nice photo-montage.
very well done. yes the shadows coming from the mailbox seems just a tad too blue.
i think you need to lower the amount of GI the white is generating to o.8 or so.
I think that i need to render out a mask for the white parts and fix it in photoshop
Lighting looks good. I would add some bump or displacement to your roof tiles. They look a little flat right now (In contrast to the existing structures).
Here’s another view, different color.
Again, i don’t think that the white trim is matching the photo correctly, but i need to wrap this up very quickly and i’m sure that this is an overkill as it is.
For both of these, i think that shingle is the main flaw of these images. But, i don’t have any textures with a suitable bump or displacement map (i actually modified the bump map for this myself) so this will have to wait until i have some time to spare on creating a nice displacement map.
Everything else, i think i’ll fix it in photoshop, either by hand, or by rendering some masks.
I’m on a laptop right now, so feel free to report any color issues
Also, i added a bit of noise to the second image, and i think it’s a bit too much. I need to install alien skin for this.
i think the soffit linit may be a bit too light compared with the house next door and i think theres a light leak or something on the bottom of the posts - could just be colour bleed from a white 3d ground thats been cropped out?
i think both are excellent matches to the photo’s though in terms of lighting!
along with that the others said, I would remove the chromatic abberation. It just doesn’t really add to the image IMO.
These are the finals i guess.