Step 1: Verify Internet connectivity
Step 2: Verify account settings (POP / IMAP)
Step 3: Verify MX Records are pointed correctly
Step 4: Verify that the correct email address is on the user account
Step 5: Check the Junk-Mail folder on web application
Step 6: Check for an Outlook error code and refer to our common error code resolutions or visit the Microsoft knowledge base
Step 7: If receiving large attachments, increase the server time out or login to account and move any large emails to a folder other than the Inbox. Then click send / receive in the email client
Step 8: Disable email scanning
Step 9: Check Outlook version and download any available updates