I recieved the following error email from Microsoft Exchange although the email that I was sending to was correct and I send to this email address a lot and it always goes through except for this time, any idea on what actually happened. Delivery has failed to these recipients or distribution lists: The recipient's e-mail address was not found in the recipient's e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator. Diagnostic information for administrators: Generating server:******** *email was correct* #550 5.1.1 RESOLVER.ADR.RecipNotFound; not found ##

This may be because of caching of old email address of users exists in outlook profile. Cache info can be wiped out by through the following procedures: 1. Search for .NK2 file and deleting it. 2. Change the Outlook to non-cached mode to ensure it is not a cached entry from the Offline Address Book. 3. Check the behaviour in OWA to confirm the server is generating the correct address list and has updated the GAL.Regards from www.windowsadmin.info