There are five general reasons why a user may not be receiving notification emails.

• The email was sent to the spam or junk folder.  To ensure this does not happen, have your users or your IT department white list system@litmos.com or the IP address 208.117.52.25 (subject to change).
• The email address has been entered incorrectly into Litmos.  Check each failed email address and verify that it has been entered correctly.
• The profile has a different email address in the user profile then the email the user is checking.  Verify with the user that they are checking the correct email.
• No email address has been entered into email field of the user profile.
• Their corporate firewall is blocking emails from the domain @litmos.com.

Also, keep in mind that the email may not be sent immediately.  Please give the system a few minutes to process the email.  You can verify that the email was successfully sent from the "Recent activity" sub tab within the user's profile.