I have just set up my email accounts and I can receive mail but it will not send.

Do you get any error?

Hi,

Have you upgraded to Windows 10? If so, please try the following method and check if it helps:

1. Close all applications.

2. Search for <cmd>, Right click and select "Run as Administrator"

3. In the command prompt window type in
         sfc /scannow       

4. Let it run to completion

If you are not using Windows 10, please follow the steps listed in the following KB article to troubleshoot the issue:

https://support.microsoft.com/en-us/kb/813514

Hoe this helps.

Regards,

Steve Fan
TechNet Community Support