9:30AM Pacific — MAX Mail customers using Office 365 and that are relaying outbound  mail through our systems may be experiencing R1 rejection errors on some outbound messages.  Microsoft has recently changed the IP addresses used to send outbound mail, and has not published those IPs.  We are attempting to determine the new set of IP addresses.  In the meantime, customers who are experiencing this error may temporarily reconfigure Office 365 to not relay outbound messages through our service.