A certain email (and maybe more) is rejected by zoho completely and does not even show up in our spam folder.
I know this is the case because they also cc a gmail account that we have as well as sending it to our zoho account.
All emails that do not pass the spam filter should go into the spam folder. No exceptions. There should NEVER be a time when an email is simply doesn't show up.
We have lost thousands of of dollars of profit from this one issue. That we know of at least, maybe more.
How do I fix this?
By the way, adding an email or domain to an allow list is not a fix as it won't stop this happening in the future with other emails.