Email Deliverability : SPF Record
You can see what, if any, your domain already has here:
https://mxtoolbox.com/SuperTool.aspx?action=spf%3aYOURDOMAIN.COM&run=toolpag
To make it work, your IT person can add spf.turntree.com to the list of SPF records and it will let you send via TurnTree mail servers without issue. In addition, if you prefer to use your own mail server, reach out to TurnTree Support to help you set it up