Hello, Users receive an error when they try to create a calendar entry via OWA. If they are using Outlook it works just fine. Here is the message: Your message did not reach some or all of the intended recipients. Subject: Sent: 5/21/2010 11:48 AM The following recipient(s) cannot be reached: Microsoft System Attendant on 5/21/2010 11:48 AM The message could not be delivered because the recipient's destination email system is unknown or invalid. Please check the address and try again, or contact your system administrator to verify connectivity to the email system of the recipient. <ExchangeHostName.DC.DC.DC #5.1.2> All of the Exchange services are running and mail is flowing. We had a catastrophy two weeks ago where we had to re-instal the OS and Exchange, due to a controller and back plane failure, which destroyed both mirrored drives. We had to call MS Support and they worked through the recovery. Now we have this error. Thanks Larry

Hi, How many Domian Controllers in the network? Please ensure that all the domain contorllers have been replicated with each other. Does the issue occur when you try to send meeting to individual users? Please try to check the legacyExchangeDN on each user. Regards, Xiu

If this is a result of that catastrophe, call Microsoft and ask them to re-open the ticket since you're not completely fixed yet. -- Ed Crowley MVP "There are seldom good technological solutions to behavioral problems." . "laj7777" wrote in message news:c83dc064-0ea1-4e09-b59a-5a247a2f38f8... Hello, Users receive an error when they try to create a calendar entry via OWA. If they are using Outlook it works just fine. Here is the message: Your message did not reach some or all of the intended recipients. Subject: Sent: 5/21/2010 11:48 AM The following recipient(s) cannot be reached: Microsoft System Attendant on 5/21/2010 11:48 AM The message could not be delivered because the recipient's destination email system is unknown or invalid. Please check the address and try again, or contact your system administrator to verify connectivity to the email system of the recipient. <ExchangeHostName.DC.DC.DC #5.1.2> All of the Exchange services are running and mail is flowing. We had a catastrophy two weeks ago where we had to re-instal the OS and Exchange, due to a controller and back plane failure, which destroyed both mirrored drives. We had to call MS Support and they worked through the recovery. Now we have this error. Thanks Larry Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."