HiWe are having some problems when we e-mail one of our customers. We get a reply from the Exchange 2003 SP2 server saying "relay access denied" but when I check the Exchange logfiles I can see the cause is greylisting.Is this our Exchange server or the recipient's mail server?I have been told that the there is a problem/bug with Exchange 2003 and greylisting where it doesn't properly send the mail within the time periode defined in the greylisting at the recipient.Am I completely wrong or?/LasseLasse

Hi Lasse, The NDR generated by greylisting should be 4.7.1 try again later. You mentioned you get a NDR indicated relay access denied. Thats a different issue and should not have any relationship with greylisting. Please help me confirm if the NDR is 5.7.1 unable to relay, if so, please see our FAQ for this issue: How to troubleshoot NDR message 5.7.1 unable to relay issue? http://social.technet.microsoft.com/Forums/en-US/exchangesvrgeneral/thread/d46bf491-0e5b-4b9e-81b3-81c66b6ad81c#5 If its not 5.7.1, please paste the complete NDR here. I have been told that the there is a problem/bug with Exchange 2003 and greylisting where it doesn't properly send the mail within the time periode Greylisting isnt a component of Exchange, if you have any issue regarding its function, you should contact the corresponding developer for further help. A related article for you reference: http://www.petri.co.il/greylisting_in_exchange_2003.htm Thanks, Elvis