Recently a server of ours went down and was rebuilt. The server hosted a website, and had links to various resources as well. At the moment, everything seems to be up and the website is accessible, except for one link: on the page is a link that when clicked is supposed to send you to the outlook web app login page. (Exchange is installed onto another server.) Before the server went down the page would load and people could get to their e-mail via the internet. Now, when you click on the page it results in a "server not found: can't find the server at [the website you're on]." However, the outlook office program and email connections on mobile devices like phones and ipads are still working correctly, pointed at that address, "mail.[address]." that address is just not accessible via the internet, and I don't know why.
Details: Exchange Server 2010
[Update] When we put in the ip for the server instead of the address name it works.