Let us take a look as to how an Outlook client connects to an Exchange 2013 mailbox.
Outlook queries Active Directory for SCP record, which is the AutoDiscoverServiceInternalURI set by the Exchange administrator. Active Directory hands back the autodiscover url and the Outlook client connects to the autodiscover service and gets the information for all the Exchange urls.
Assuming that the CAS servers are load balanced using NLB or HLB, Outlook connects to one of the CAS servers. The following happens after that. (The below diagram is from one of the TechED NA Exchange session).
- CAS servers authenticates the incoming connection.
- Once the user is authenticated, CAS looks up where the user mailbox is.
- CAS server finds which mailbox database hosts the mailbox for the user and in turn finds which server hosts the active copy of that mailbox database by querying the Active Manager.
- CAS proxies the connection back to the mailbox server which is hosting the active copy of that mailbox database.
- For any mailbox connectivity, the user is always served by the server that hosts the active database copy. CAS only authenticates and proxies the connection.
- Within Outlook, the server name will be the mailbox guid @ the smtp domain. This is different to an Exchange 2010 connection where the server name is the CAS array.
- Next time a connection is initiated by the same user, any one of the CAS server will pickup the connection and proxies it back to the relevant mailbox server. As all CAS servers will have the same certificate, the user will not be prompted again for credentials.
all my clients suddenly stopped connecting to the mail server. even from mobile devices. we did not make any changes when this happened. we have over 10,000 clients. no error messages more than cannot connect to server
am desperate
Hi Lanre,
Which version of Exchange & Outlook do you have?
I have been uneventful in manually adding the server name for manual setup of the mail profile for Outlook 2013 since we recently upgraded to Exchange 2013. I can use autodiscover just fine, and I can add mailboxes automatically or by using the new button for adding an account to an existing email setup; but previously I was able to do this manually by selecting the server, and the email. I have tried with the mailbox guid @primarydomain.org (our primary domain) and it will not work as in previous versions 2010, 2007, etc.. What am I missing?
We see this message: “Outlook cannot log on. Verify you are connected to the network and are using the proper server and mailbox name. The connection to Microsoft Exchange is unavailable. outlook must be online or connected to complete this action”
Hi Jose,
I need your help, in Configuring Outlook 2010 with Exchange Server 2013.
Is there any post installation tasks that needs to be completed at Server side or any certificates needs to be installed at server side. since i am getting the below error when trying to configure the mailbox in Outlook 2010.
‘The connection to the Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action’
But I am able to connect to mailbox via OWA and able to send / receive mails.
Please help!
Hi Mahesh,
You need Outlook 2010 SP1 with November 2012 Cumulative Update as a minimum to connect to 2013.
Yes, you need certs as well, but that shouldn’t stop you from connecting (you will get certificate prompts though).
Very interesting thanks!
When you create an Outlook profile with a different user than the current logged Windows user, Outlook can not use autodiscover. For example, you open your Windows session with Rajith, but you need to test Harry Profile.Do you know how you can do? Becase of new Outlook reference, it seems to be complicated (configure manually Outlook anywhere, precise GUID for server, etc.)