how to whitelist an email address

Hello

I’ve been experiencing not receiving automated email form submission notifications from Jotform.com, a secure and widely used online form platform (https://www.jotform.com). These emails are sent from the following sender domains

• [Edited: "Personal Information"]

Despite these addresses being added to my contacts and not being marked as spam, the messages do not reach my inbox, spam folder, or any other folder. I’ve confirmed that the messages are being successfully sent by Jotform and are being delivered to other email addresses (e.g., Gmail), but not to my Comcast account.  I've created a rule to allow them to my email but with no success. 

This strongly suggests that the emails are being silently blocked or filtered at the server level.

This is affecting my ability to receive important form submissions and automated notifications and makes it impossible to use Jotform without a different email address.

Can you assist in resolving?