One user From Web TimeSheet does not receive email notifications

Scenario:
One specific user is not getting the email notifications, however all other users are getting notifications.

Cause:
Exchange Server Intelligent Message Filter provides server-side message filtering,

Resolution:

• Check the Exchange Server if the user has set up email filters to block the emails from the WTS application.
• Disable Exchange Server Intelligent Message Filter in Exchange Server. Emails will start triggering.
• For more information follow the steps listed in the article given in the link (https://campus.barracuda.com/product/emailsecuritygateway/knowledgebase/501600000013TKsAAM/how-can-i-disable-my-spam-controls-on-my-microsoft-exchange-server/)