I use my domain at gmail, and forward to zohomail. Everything is worked, but 2 day ago its not delivered... I get this mail:

Delivery to the following recipient failed permanently:

      info@muszerfal.hu

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain muszerfal.hu  by  mx.zoho.com . [165.254.167.50].

The error that the other server returned was:
541 5.4.1 Mail rejected by destination domain

What can we do?