If email sent from your website is not received it may be being rejected by our mail system.
Make sure your script is sending email address with the configured sender being an email address you have configured on your hosting account. The script may be using SMTP, the PHP mail() function, or sendmail (/usr/sbin/sendmail) for example. (Additionally, if your script is talking SMTP natively instead of using one of the other methods you will be required to authenticated using SMTP AUTH, please consult the documentation on the script for information on how to do this.)
If you cannot configure the sender specifically in your script then the system will use the default address of email@example.com where yourdomain.tld is the domain name of the web site which is sending the email. If that is the case then you will need to create this email address on the account.
If you are using PHP and it's mail() function, see the manual http://php.net/mail and reference the additional_parameters section.
mail("firstname.lastname@example.org","Test Subject","Test Message","From: email@example.com","-f firstname.lastname@example.org");