DKIM + mail forwarding + inability to receive emails 100% of the time

DKIM + mail forwarding + inability to receive emails 100% of the time

Hello,

I cannot get DKIM verified and I have followed your instructions to a T. Don't know what else to do.

Email forwarding does not work, I don't know what else to do about that and this is something everyone in my team will need for a couple of months.

I sometimes get emails, other times can't get them. The error message that pops-up is this:
The response was:

553 Relaying disallowed


Final-Recipient: rfc822;  isa@handpickedfromportugal.com
Action: failed
Status: 5.0.0
Remote-MTA: dns;  mx.zoho.com . (204.141.32.121, the server for the domain  handpickedfromportugal.com .)
Diagnostic-Code: smtp; 553 Relaying disallowed
Last-Attempt-Date: Wed, 25 Oct 2017 02:03:10 -0700 (PDT)

Please help, I have to present Zoho to the rest of the team to get their approval, and if it doesn't work they will most definitely want to use it.

Thank you