Receiving emails from Zoho saying "Problem while forwarding... FINAL WARNING" -- but there isn't a problem!

Receiving emails from Zoho saying "Problem while forwarding... FINAL WARNING" -- but there isn't a problem!

See email below... I'm getting emails from Zoho Mail Mail Administration saying there's a problem while forwarding mails... But there isn't! I AM getting the emails -- see below!

Quote
Dear brent@brentreid.com,
Problem while forwarding mails to davidbrentreid@yahoo.com. Repeated failure will disable email-forwarding.

Regards,
Zoho Mail Mail Administration
Unquote

Please advise?

     Brent Reid