What ports does Exchange MAPI/CDO use to connect to the Client Access Server from the Mailbox Server. I have a piece of software installed on a Mailbox server that uses Exchange MAPI (RDO to be specific, which uses Exchange MAPI). The problem is I'm running into MAPI_E_NETWORK_ERROR problems so I was wondering if there might be firewall issues i.e. the Client Access Server (CAS) cannot be accessed properly from the Mailbox server by MAPI. what ports do I need to check in the firewall configuration? This is on Exchange 2010
What ports does Exchange MAPI use
exchange-2010
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From the playing around i have done i don't think you can view 2007 mailboxes using CAS2010 unless it proxies to a CAS2007. I have found this which seems to say the same thing:
CAS 2010 can only open 2010 mailboxes; it cannot connect to 2003 and 2007 mailboxes. The only time CAS2010 will do anything OWA related with 2007 is if the user's mailbox lives in a non-internet facing AD site and only has CAS2007 boxes in that AD site. When this happens the CAS2010 box in the Internet facing AD site will proxy to CAS2007, which in turn opens the 2007 mailbox. In this one particular case you'll have to copy the CAS2007 binaries to the CAS2010 server for this to work.
This also seems to confirm that it can't be done: http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/96d63d71-c536-4dab-a401-f26c425c29c9
Sorry i couldn't provide a solution.
That setup doesn't sound too ridiculous to me, and I wouldn't change much. I'm assuming all the preparatory work has been done (such as multiple Active Directory Sites, Domain controllers in each site etc.) so I won't go into great detail about that. If you can stretch your budget a little bit, I would tweak your CAS topology a little bit to eliminate the SPOF.
You can install the Hub Transport role on your Mailbox servers and they will automatically load balance themselves according to the Active Directory site they reside in. That's a quick and easy win, and I can't see that much of a reason not to do this.
If your budget can accomodate 2 hardware load balancers, you can also install the CAS role on the Mailbox servers as well. You'd then create A records in DNS for your load balancers and configuire the appropriate Mailbox Databases in each site to use the CAS Array for the site.
To do this, issue the command New-ClientAccessArray -Fqdn "ex-sitename-casarray.acme-widgets.com" -Site "AD-Site-MAIN" for each site (replacing your A records and real AD Site Names as appropriate).
Then issue Set-MailboxDatabase "<<Appropriate Database>>" -RpcClientAccessServer <<site-casarray-name.acme-widgets.com>> to make sure your Mailbox Databases use the CAS Array.
It is best to have a local copy of a users Mailbox in the same site as the user, so I would create 2 Mailbox Databases each replicating to a Mailbox server in the same site, as well as the other site (I've done a diagram to visualise it for you). For users in the MAIN site, home their Mailbox on the Main Mailbox DB and for users in the SUPPORT site, home their Mailboxes on the Support Mailbox DB.
Best Answer
MAPI actually uses RPC which uses a dynamically assigned port number. Here's a blog posting that will help you make that port number static:
http://social.technet.microsoft.com/wiki/contents/articles/configuring-static-rpc-ports-on-an-exchange-2010-client-access-server.aspx