Is the business relaying through your server? If so, their SPF record 
has to include your IP in it as well as their own.

Steve wrote:
> I think someone might have posted about this before.  But I didn't read
> about it.  
>
> I have only one customer who is a business who is sending email out from a
> server with a report from their backups through our surgemail server.  It is
> getting rejected by Godaddy with this message
>
> (IP ADDRESS) before data sent: 550 5.7.1 SPF unauthorized mail is prohibited
>
> We are using SPF and we are not blacklisted nor is the sender blacklisted.
> Any idea what the issue could be?   
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