All emails generated and sent via your Jackrabbit database are sent from our own servers.
Our domain is jackrabbittech.com and our email servers IPs are:
22.214.171.124 through 126.96.36.199, and 188.8.131.52, 184.108.40.206, 220.127.116.11, 18.104.22.168.
In order to help ensure proper delivery of emails to your customers' inboxes, they can add senders of legitimate emails (such as your organization) to their Whitelist, also called the Approved or Safe Sender list.
Curious "how" to whitelist? Or tell your customers how to whitelist? Here is a great reference page to share with them: How to Whitelist Email.