Here is my problem. I can't access my /owa or /remote externaly on sbs 2011. It worked before and I don't know the reason why it stopped working. I can access the site with my internal ip/owa and /remote but externaly I can't. I've tried to open all the ports linked to sbs 2011 (25, 80, 443, 987, 3389) but that doesn't work. After that, I even put the sbs server in the dmz to be sure that something else wasn't blocking this but it still didn't work.
In IE I get a 404 error and in chrome I get this error : getfile: Cannot open URL(/etc_ro/web/owa,No such file or directory)
To test, I tried to access remote desktop with the mstsc command and the external ip adress and it worked.