The email may be delayed in arriving to their inbox, or may have been considered junk/spam. Please advise your client to check the spam/junk folder before requesting.

They can also follow this troubleshooter as a starting point https://support.click4time.com/index.php?/Troubleshooter/Step/View/8

IMPORTANT!! If your client accesses their email through another mail program such as Outlook, Thunderbird or through their mobile device's email app, and their email provider (Yahoo, Hotmail, Gmail, company email etc.) considered the email as junk, it likely won't be retrieved by their mail program. They will need to log in to the webmail system directly through a web browser to check the spam folder and mark any Click4Time email as "Not Spam". They should also add Click4Time's sender email "notifications@mailer.click4time.com" as a contact so that their mail service knows to trust emails from this address. This should fix any deliverability issues.

Microsoft Outlook example

Once email has been sent from our server and received by the incoming mail server, we have no further control over where emails are directed.

If they are still having difficulties locating missing emails, please contact us at support@click4time.com for further assistance.