We're no longer receiving notification emails from either of our two forms on our site, which is hosted at GoDaddy. We're using the Divi theme, Divi forms, fluentSMTP plugin, and Brevo as our mailer. The email logs show that most emails are being sent, but not all. Thankfully, all form submissions are captured in WP. For now, we're using the Divi db to monitor our form submissions.
Previously, three of the email addresses were receiving the emails, and only the email address with the same domain as the website was not. This particular email address is hosted with GoDaddy and uses Microsoft 365 Outlook. The others are Gmail accounts.
We have a dev version of the site hosted on a HostGator server and it's working fine, so it has to be something with GoDaddy, I would think. What are some things I can check?