Hi Everyone! I have a problem with Exchange 2010. The Server is set up 3 weeks ago and was running without any problems. But I recently moved some mailboxes with local move request to a new database on a more secure location on the server. Then, I deleted the original mailbox database. Now the mailboxes and users which had the exchange account installed in their Outlook earlier are OK. But when I add the Microsoft Exchange account to the client computers in Outlook, I cannot access the address books. The error is "The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action." However, they can receive e-mails, and reply e-mail messages. Can anyone help me? Best regards, Shahab

Shahab, If you are trying this internally, check whether \\exchangeServerName\ExchangeOAB is accessible now?Regards from ExchangeOnline | Windows Administrator's Area

Hello, what client do you use to access mailbox? Is it Outlook 2003 /2007/2010 /2013? Do you have OAB enabled for web distribution? Please run the Test E-mail autoconfiguration (CTRL + right click on Outlook icon in notification area -> fill in your SMTP address and test if you get correct and accessible OAB virtual directory) Link to web article: http://ficility.net/2013/05/10/exchange-autodiscover-service-overview-encz/ With regards Zbynk

Dear ManU, I have access to ExchangeOAB from clients.

Dear Zbynk, The clients are using Outlook 2010. The OAB is enabled for Web Distribution. The result to Test E-mail autoconfiguration is "Autoconfiguration was unable to determine your settings!"

Hi again, I found the source for this problem. Microsoft Exchange Address Book Service is marked as automatic, but will not start and cannot start manually either. It gives the following error message: "The Microsoft Exchange Address Book service on Local Computer started and then stopped. Some services stop automatically if they are not in use by other services or programs." Can you help me please?

Problem solved. The Microsoft Exchange server should be a GC. I changed it to DC a few days ago.