Just had my first client with this issue. I downloaded NK2Edit trial and changed the type from MAILTO to SMTP for the address with the issue and so far so good. I didn't see the patch on their PC, but was under a bit of urgency to get it fixed so I may have missed it. For what it's worth, Environment is Outlook 2010 / Exchange 2010 Win7/Server 2k8R2. I have several clients around the city so if it comes up again i'll post more details. Thanks, keithKeith Copeland

Hi Keith, I find you involved in this thread: http://social.technet.microsoft.com/Forums/en/exchangesvradmin/thread/56b2d50d-6855-444b-abed-89aaa9176a9f You told the patch is KB2344993? I'm research the issue and will update it soon. Please wait. Frank Wang TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hello, Is the delivery failed message in this case the same as reported in the other thread? Is it happening after installing the KB2344993? If so it looks like there may be an update coming out towards the end of the month... Also, the following workaround has been supplied: • Click Tools > Options • Click the Mail Format tab • Click Editor Options • Click Proofing • Click AutoCorrect Options • Click the AutoFormat Tab • Uncheck "Internet and network paths with hyperlinks" • Click OK, OK and OK Please let me know if this makes sense or if i am missing something... Kevin Ca - MSFTKevin Ca - MSFT