Email not sent from webserver

Email not sent from webserver

I have a GoDaddy hosted domain set up for email with Zoho.

My webserver sends emails just fine to other email domains OK, but not the email I have configured with Zoho.

I can send email from gmail to my Zoho email.

All my statuses (Verified, MX Records, SPF, DKIM) have green check boxes indicating that all is setup/verified.

Seems like Zoho doesn't want to relay email from the webserver though. What am I missing?