Problems forwarding to Yahoo

Problems forwarding to Yahoo

I received an email with the following:

Subject: WARNING :: Need immediate action

Dear michelle@michellecohron.com,

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

Regards,

Zoho Mail Mail Administration


Can someone tell me what kind of problem there is with forwarding to my Yahoo account? This warning message was forwarded without any issue, so why can't other mail? Details will help me figure out what is wrong.