Some recipients not receiving our emails

Some recipients not receiving our emails

Hello, we are experiencing a problem with zoho mail. Our clients has been telling us that they are not receiving some of our emails. There was an instance that I was Bcc'ed and I received the email but the clients did not. This has happened multiple times already. I check on the sent box and the email was sent successfully to all recipients  and as stated on your documentation:

Email Delivery Failure

If the email is not delivered to some of the mentioned recipients, or to any of the recipients, it is indicated with the Delivery failed icon.


There was no problem sending the email.

We need an urgent solution for this. 

Thank you