Contact Emails Never Arrived

Hi,

Several times now I have found a “legitimate” contact form in the report I receive from Clean Talk, but the contact form never arrived in my email. I have backup email set up at gmail and the email does not arrive there either. Also, when I check my website database there is no submission for the contact form.

Is this some type of firewall issue? How can I prevent it from happening.

Thank you,
Kim