Very odd one. Appears to be from the upgrade to Windows 10 people are reporting. I’m sure I installed Office 2010 after Windows 10 was installed so shouldn’t of caused an issue.

But anyway. E-mails will just sit in the Out box and never send with errors such as:

Sending reported error (0x800CC13) Cannot connect to the network. Verify your network connection or modem.

Being throw back.

Simple fix in the end it appears. Run CMD as Admin and type sfc /scannow

Once scan is finished it appears to fix the issue.

Press windows key an x to get an admin user command prompt

then

type

sfc /scannow

http://answers.microsoft.com/en-us/windows/forum/windows_10-other_settings/windows-10-upgrade-prevents-outlook-2010-from/311f421b-da0e-4ad2-ba2d-a153481b1d31?page=1