get email working

I have two email accounts, one personal (on verizon.net) and a business email associated with my business web site running on bluehost. The verizon.net email is working fine. The problem is with the business email - I can receive emails no problem, but if I send an email through my desktops running MacOS - either through Outlook or the Mac email program - the emails are somehow being intercepted and changed to spam. Cloudmark is flagging these and they are not going through - instead I get a return msg like this:

Your interface would not accept the details here, so I am attaching them in a file