MSN.com does not have its own email service per se, but it does support Hotmail. Hotmail is an email service owned and operated by software giant Microsoft. Hotmail and MSN both fall under the Windows Live umbrella, and as such you can check your Hotmail account from MSN.com.
Open your web browser and navigate to msn.com.
Click the "Hotmail" link in the upper right-hand corner of the MSN homepage. Hotmail is the email service of MSN.
Enter your Windows Live ID or Hotmail username and password in the boxes and click the gray "Sign In" button. In the new page that opens, click on the blue "Inbox" link to see your emails.