Hi All, We are having trouble with staff unable to send emails to distribution groups Specifically, we are using a "mail uniuversal distribution group" in Exchange 2010. The distribution group contains 2 group members: normal staff who are in one OU, and IT staff who are in another OU. Users permitted to send are all authenticated. When you try sending from Outlook 2010, we can find the "All Staff" distribution entry in the address book, but what is strange is it does not turn bold/we cannot "expand" it. But when we send, shortly after the user receives an NDR Delivery has failed to these recipients or groups: All_Staff_DG The email address that you entered couldn't be found. Check the address and try resending the message. If the problem continues, please contact your helpdesk. Diagnostic information for administrators: Generating server: W2K8WTC23.domain.internal IMCEAEX-_O=DOMAIN_OU=First+20Administrative+20Group_cn=Recipients_cn=All+20Staff@domain.org #550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found ## Any ideas? Thanks :)

Well just to update. I deleted the local OAB on the client and reopened Outlook, which seemed to work - but it looks like outlook web app users are still having this issue :/

Hi Steven, Go to the properties of the group and make sure the E-mail addresses has the correct address. Check the Alias on general tab too.MCSE | MCITP - Server 2008 | MCITP - Exchange 2007 | MCTS - Exchange 2010

Seems OK now touch wood ;) OWA just needed to be closed and re-opened. Email address and alias all spot on Thanks for your help

Glad you sorted it out. Good luckMCSE | MCITP - Server 2008 | MCITP - Exchange 2007 | MCTS - Exchange 2010