Several months ago we migrated to Exchange 2010 from a different domain by exporting and importing PST files. The migration went smoothly but some users are having an issue sending meeting invites. They are getting errors like the following: Delivery has failed to these recipients or groups: Intended recipientYou can't send a message on behalf of this user unless you have permission to do so. Please make sure you're sending on behalf of the correct sender, or request the necessary permission. If the problem continues, please contact your helpdesk. This is happening with there personal distribution groups as well as those from the GAL. I have tried deleting the old autocomplete addresses and even deleting the OAB and downloading a new one. This even happens to address newly added to distribution groups and also outside addresses. Does anyone have any other ideas? Any help would be appreciated.

Make sure the users sending out the meeting invite are sending as themselves and not someone else. I have users that like to look at their calendar and others when creating a meeting request and if they are focused in another users calendar when they click the new meeting button, Outlook will attempt to create the meeting request as the other user, what you reported above is a result of this and the user not having send-as or send on behalf rights to the other persons account.

Thanks for the reply but unforfunatly that is not the case. The user was sending the invite from her calendar, she did the invite twice because as you thought, she was sending from the wrong calendar.

Can you let us know what the senders email address is and paste the entire NDR into the post?

The sender is Pat.Sample@mnchurches.org The NDR: From: Microsoft Outlook Sent: Wednesday, September 19, 2012 11:19 AM To: Pat Sample Subject: Undeliverable: Staff meeting Delivery has failed to these recipients or groups: All MCC Staff You can't send a message on behalf of this user unless you have permission to do so. Please make sure you're sending on behalf of the correct sender, or request the necessary permission. If the problem continues, please contact your helpdesk. brusche@jrlc.org You can't send a message on behalf of this user unless you have permission to do so. Please make sure you're sending on behalf of the correct sender, or request the necessary permission. If the problem continues, please contact your helpdesk. alison@jrlc.org You can't send a message on behalf of this user unless you have permission to do so. Please make sure you're sending on behalf of the correct sender, or request the necessary permission. If the problem continues, please contact your helpdesk. Diagnostic information for administrators: Generating server: /O=MCC/OU=EXCHANGE ADMINISTRATIVE GROUP (FYDIBOHF23SPDLT)/CN=RECIPIENTS/CN=All MCC Staffaba #MSEXCH:MSExchangeIS:/DC=local/DC=MNchurches:MCC-MAIL[578:0x000004DC:0x0000001D] #EX# brusche@jrlc.org #MSEXCH:MSExchangeIS:/DC=local/DC=MNchurches:MCC-MAIL[578:0x000004DC:0x0000001D] #SMTP# alison@jrlc.org #MSEXCH:MSExchangeIS:/DC=local/DC=MNchurches:MCC-MAIL[578:0x000004DC:0x0000001D] #SMTP#

Does this happen for every user on the new Exchange 2010 system? Does it happen on new meeting requests or just updating old ones? Also, is email working properly? Can this user email to the MCC Staff group?

Does not happen to every user. Does happen on new and old meeting request. Yes they can send email to MCC Staff group.

Ok, how about using OWA? Does the issue only happen in outlook? If it only happens in outlook, I would recommend emptying the auto complete list, deleting suggested contacts, go from there. After that, try deleting the users OST file. Then, a new outlook profile on the PC.