If you’re getting a bunch of spam mail, it doesn’t necessarily mean you have a virus. It means that you have an email account with a poor spam blocker or you are sending out your email address to too many disreputable sites that use it to spam you.
You can end the problem by simply either changing the options of your email account to be more restrictive in who you receive emails from or get a new email account.Gmail and Thunderbird are very good, hotmail and yahoo are pretty poor at containing spam mail.
If you still believe it’s a virus then download and run these free virus scanners to rid yourself of the problem.
Malwarebytes (very good, one I use and recommend) malwarebytes.org/
Microsoft Security Essentials (never used, but it’s very good aswell and I recommend it too) windows.microsoft.com/en-US/windows/products/security-essentials
Hope your problem is solved.