I was asked about this a while back and thought I would share.  This person has e-mail receiving problems, so I wanted to turn on logging and check that the network ports were really open on his PC:

To get a mail log for more details – go to Tools/Options – then the advanced tab/Other button/Enable logging.

(mine is not checked – put a tick in yours).  The location of the log file can be found at:

MAPI (Exchange), POP3, and SMTP transports  - The log file has the name OPMLog.log and is located in one of the following locations:  c:\Users\user name\AppData\Local\Temp\Outlook Logging - note this is the location on Windows VISTA

 

You might also want to look at http://www.webpipe.net/howto/Outlook_0x800CCC0E.  You will need to install  at telnet, but this is documented as:

By default, Telnet is not installed with Windows, but you can install it by following the steps below.

To install Telnet Client

1. Click the Start button , click Control Panel, click Programs, and then click Turn Windows features on or off. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

2. In the Windows Features dialog box, select the Telnet Client check box.

3. Click OK. The installation might take several minutes.

If the telnet works, but Outlook cannot get mail, try running “outlook /safe” and see if the same problem happens.  If it does not, then it is an add-in.

ttfn

David