Any time you see "Relay access denied" it generally means the server handling
the email (recipients mail server) cannot deal with it.
This may be for a number of reasons:
- a misconfiguration
- it's not meant to
be dealing with it
- there is a mistake with the mail routing/DNS
We suggest in the first instance you check with the recipient. Failing that we can dig further into the logos and see if we can shed any light on it.
You should also check that the email address you are sending to is valid - you can use the Email Dossier at http://centralops.net/co/ to do this.