We have problem Mail bouncing in all our company email? we are using Exchange 2013. Any one can give proper solution?

Hi,

First, make sure your domain is in accepted domains (Get-AcceptedDomain, New-AcceptedDomain).

Second, make sure the Default receive connector has the right permissions.  Run Get-ReceiveConnector | FL Name,PermissionGroups, and add AnonymousUsers to the list if it isn't already there.

If neither of those fix the issue, post the NDR you are receiving.