If you are having problems with your Exchange server, you have a number of sources for assistance.
You can Google for the problem, and in many cases this will bring up something that can assist you.
If you have a fairly specific problem though, you might need to actually explain it to someone to get assistance. For that you have two main sources.
1. Microsoft Support - this is of course a chargeable solution.
2. Peer to peer support.
The second option is very popular and is where you can get assistance from some of the top Exchange experts. Exchange MVPs (like myself) post in peer to peer locations, as do some Microsoft employees.
Where to find peer to peer support
With the demise of the Microsoft Newsgroups, peer to peer support pretty much comes in two forms.
One of the most active email lists was hosted by Sunbelt Software, who were acquired by GFI. GFI have now announced the lists are going away, so the new list can be found at "My IT Forum" http://myitforum.com/myitforumwp/services/email-lists/
Yahoo Groups also have email lists for each version of Exchange, however these appear to be very low traffic.
Use an Outlook.com account or a public folder to store the list traffic - they can get very busy and by putting the content in to a separate place it will keep it from your main email.
There are lots of forums where you can get support for Microsoft Exchange.
Exchange 2013: http://social.technet.microsoft.com/Forums/en-US/category/exchangeserver
Previous Versions: http://social.technet.microsoft.com/Forums/en-US/category/exchangeserverlegacy
Very busy forums, which are monitored by Microsoft staff. However there are a lot categories therefore working out where to post can be a challenge.
The Exchange section is very active and is one of the main places you will find me posting. Contrary to popular belief, you don't need to pay to either see the solutions or post a question. A free account can be created here: https://secure.experts-exchange.com/expertSignUp.jsp
Exchange 2000/2003: http://www.petri.co.il/forums/forumdisplay.php?f=12
Exchange 2007/2010/2013: http://www.petri.co.il/forums/forumdisplay.php?f=36
Another forum where you will find me posting, I also moderate the Exchange forums. Not quite as busy as some, but knowledgeable people post.
Another forum divided in to categories.
There are other forums out there, but have very low traffic, which means your question may go unanswered.
You can also find groups on Linked In, if you have an account there.
More ways to get assistance can be found on my list of Exchange resources at http://exbpa.com/