Run the Virtual Technician to see if that fixes it.
If not, after making sure your system is totally up to date, I suggest contacting Technical Support, free by phone or online chat and linked under Useful Links at the top of this page.
Check for malware using Stinger and Malwarebytes Free, both in the last link in my signature below.
Make sure your system is totally up to date, including any parts you don't use including Internet Explorer.
You should have no problem linking up with the Technical Support department if everything is up to date and no infection present.
The Anti-Spam service is just one of many services running on your computer. Sometimes something goes wrong and the service stops running. Quite why the service should stop is an interesting question, but you can tell the system to restart it if it fails.
On XP, go to Start-->Run and enter services.mc
On Vista or Windows 7, search for “Services” on the Start Menu and click on the icon at the top of the list. The Services tool will then start.
On Windows 8 type services.msc in the Run box (Windows Key + R).
You will see a list of all the services and whether they are running or not.
This bit is important : Ignore everything except the entry for McAfee Anti-Spam. Don't be tempted to modify anything else unless you've create a System Restore Point beforehand, and even then it's not a good idea to modify any of the Windows services. Results can be unpredictable. Modifying this one should be safe.
Double-click on McAfee Anti-Spam and you will see the Properties window. Make sure that in the third window it shows "Restart the service", and if it doesn't you should change the setting.
That last screenshot shows what Anti-Spam depends on to keep running. So if it keeps turning off, there may be a problem higher up the chain. At least now Anti-Spam will just restart automatically.
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