Optonline.net addresses not receiving emails

I have a handful of emails coming from optonline.net. Despite being “marketable” and opting into our emails, they are not receiving them…looking at the history of them, they are all marked red and are not in spam or junk. How do I correct this? Thanks!

I have the same issue. All of optonline.net emails show as spam and not delivered.

I have contacted some of my clients with an optonline email and they are not getting the emails, but do receive emails that I send them from my Exchange account. Don’t know how to get optonline.net to allow Infusionsoft emails.