https://community.hpe.com/t5/operating-system-microsoft/571-delivery-not-authorized-message-refused/m-p/4467815#M9441 hi<BR /><BR />Some clients from the external cannot send mails to some of our users <BR />due to the following error:<BR /><BR />571 Delivery not authorized, message refused<BR /><BR />We have Microsoft Exchange Server 2003 SP2.<BR />Howto authorize an external user at the Exchange 2003 server? Tue, 28 Jul 2009 06:50:55 GMT 'chris' 2009-07-28T06:50:55Z https://community.hpe.com/t5/operating-system-microsoft/571-delivery-not-authorized-message-refused/m-p/4467815#M9441 hi<BR /><BR />Some clients from the external cannot send mails to some of our users <BR />due to the following error:<BR /><BR />571 Delivery not authorized, message refused<BR /><BR />We have Microsoft Exchange Server 2003 SP2.<BR />Howto authorize an external user at the Exchange 2003 server? Tue, 28 Jul 2009 06:50:55 GMT https://community.hpe.com/t5/operating-system-microsoft/571-delivery-not-authorized-message-refused/m-p/4467815#M9441 'chris' 2009-07-28T06:50:55Z https://community.hpe.com/t5/operating-system-microsoft/571-delivery-not-authorized-message-refused/m-p/4467816#M9442 This may help:<BR /><BR /><A href="http://support.microsoft.com/kb/262354" target="_blank">http://support.microsoft.com/kb/262354</A><BR /><BR />Make a great day!<BR /><BR />Roger Wed, 29 Jul 2009 02:48:04 GMT https://community.hpe.com/t5/operating-system-microsoft/571-delivery-not-authorized-message-refused/m-p/4467816#M9442 Roger Faucher 2009-07-29T02:48:04Z