Having a problem where a user can't send to a handful of recipients when sending from his Outlook 2010 client. The message shows up in Message Tracking but the recipient doesn't receive it. Can send to the recipient fine from OWA and by manually sending throught telnet. If I delete the profile and recreate it, it works again temporarily. What could the problem be? It's an Exchange 2007 server.

If it's showing in message tracking and works via OWA, I suspect it's a corrupt cache. Take the outlook profile out of cached mode and also delete the .ost file from his profile.James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

I'll try that by turning off the caching, but I've already cleared the .ost and recreated the profile. It worked fine for several days after that but then started doing it again.

hi, If he can't send mail to some recipient, he should receive NDR. Have you gotten it? Please post here. Only one user get the issue? Always these recipients or not? Post your message tracking log of the message here. Try to clean the nickname cache:http://support.microsoft.com/kb/287623#FixItForMeAlways hope can help you thanks,CastinLu TechNet Community Support

Is exchange the last leg to the internet or do you have an internet smarthost? If so have you checked the smtp logs on the smarthost?James Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com

No, there is no smarthost

So you see it in message tracking where it was recieved by the user, but do you also see an entry where it was sent out to the internet connector and get a 250 response? I would also check your smtp smtp send logs to see if you see the conversation from your exchange server to this domains email server to see if they accepted it. If you dont have logging enabled, you need to set it on the send connector. http://exchangepedia.com/2007/05/exchange-server-2007-logging-smtp-protocol-activity.htmlJames Chong MCITP | EA | EMA; MCSE | M+, S+ Security+, Project+, ITIL msexchangetips.blogspot.com