Problem while forwarding mails to ___

Problem while forwarding mails to ___

We are trying to set up email forwarding, but continue getting error messages. Forwarding is set up properly and has been confirmed.

But at the Gmail address where the emails should end up, we get these messages from Zoho:

"Subject: WARNING :: Need immediate action
To: ---@---.com


Dear ---@---.com,

Problem while forwarding mails to ---@gmail.com. Repeated failure will disable email-forwarding.

Regards,
Zoho Mail Mail Administration

-----------------------------------------------------------------
This is an automated message, please do not reply"


I'm not sure what other steps we should take to get email forwarding working