Undelivered Mail Returned to Sender

Undelivered Mail Returned to Sender

Hello,

We use zoho mail for our business account.
Since yesterday emails are not getting delivered and are failing.
Below is the error.

=======================================================================================

This message was created automatically by mail delivery software.

 A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.

 

shuklamanish2112@gmail.com, ERROR_CODE :550, ERROR_CODE :5.7.1 This message does not have authentication information or fails to pass

                                           5.7.1 authentication checks. To best protect our users from spam, the

                                           5.7.1 message has been blocked. Please visit

                                           5.7.1  https://support.google.com/mail/answer/81126#authentication for more

                                           5.7.1 information. o24si844085ejb.136 - gsmtp

 

solisgridcojab@dayalok.in, ERROR_CODE :550, ERROR_CODE :5.7.1 This message does not have authentication information or fails to pass

                                           5.7.1 authentication checks. To best protect our users from spam, the

                                           5.7.1 message has been blocked. Please visit

                                           5.7.1  https://support.google.com/mail/answer/81126#authentication for more

              


                             5.7.1 information. v10si4128590edd.406 - gsmtp

Thanks and Regards
Mayank