Puri.sm email addresses not reachable

Hi there,
I am seeing “Undelivered Mail Returned to Sender” responses from M***ER-DAEMON@mx2.puri.sm (Mail Delivery System), they contain the following error:

Recipient address rejected: Message rejected due
    to: SPF fail - not authorized. Please see
    (in reply to RCPT TO command)

Looks like some misconfiguration to me, the IP is from mx2.puri.sm which is of course not in the SPF list of servers allowed to send for the FROM domain. Another possible source of the error could be the r=<UNKNOWN>