Microsoft's Windows Essentials 2012 suite reached it's end of support date earlier this week (January 10th, 2017). Windows Live Mail is one of the more commonly used products that was included.

There is an increased security risk associated with use of unsupported products past their end of support date. If new security flaws are found, Microsoft will no longer be patching them, so they'll be open for malicious users to exploit.

If you are still using Windows Live Mail, it is highly recommended to switch to something current such as Microsoft Outlook (available as a part of Office Home & Business), Outlook.com, or GMail.