Mail not being received - but MX records changed ok and SPF/DKIM verified

Hi

I have followed the Help resources to change my MX records with my domain registrar (Godaddy), and also set up the SPF and DKIM which have been verified. I deleted old provider MX records and so I should be receiving emails ok. However I'm not - test mails sent from an Office365 account get lost/not received and I get the following error:-

mx.zohomail.com rejected your message to the following email addresses:

XXXXXXXX ADMIN (XXXXXX@XXXXXXXXXXXXXXX.com)
Your message couldn't be delivered. When Office 365 tried to send the message, the external email server returned the error below. This is probably due to a problem or policy setting on the recipient's email system.

mx.zohomail.com gave this error:
Remote server returned an error -> 553 Relaying disallowed

Help would be appreciated.

Thanks in advance