Okay, so I've hit a wall here. Prior to yesterday, we were hosting out internet and DNS with WindStream. They handled everything for us with no issue. But, in an effort to not have to change DNS hosts everytime we change ISP's we made the decision to host our DNS with Network Solutions who we've used as our registrar for 20 years. I've now run into an issue where I can not send email to certain providers such as Yahoo. We use Office 365 as our spam filter and host an on-prem Exchange server. Does anyone have a recommendation for how to configure the SPF record to accommodate this configuration?