I am currently trying to set up a Desk system, and the issue which I am stuck on is that when I have a set a rule from the previous email domain to forward all emails to the new ZohoDesk One - I get a bounce back. The bounce back reads that the recipient - Zoho - is rejecting the mail. 

I did contact directly to Desk Support, but was told it was my email senders problem and they could not help -  but on forums and the Helpdesk there is no help and suggest it is the recipients error...This is of course a major issue and the system won't work at all if this cannot be solved...please can someone advise?