Exchange 2010 accessing via OWA

Does this point to your 2010 Exchange OWA? -  https://mail/owa

What if you enter: https://x.x.x.x/owa (where x.x.x.x is the IP address of 2010 Exchange)

If you don't plan on keeping the Exchange 2003, then I would suggest to remove it, as this is may also be a conflict/confusion issue:

 - http://www.msexchange.org/tutorials/Remove-Exchange-server-entire-Exchange-organization.html

get-owavirtualdirectory | fl
output the contents here.

Did you move your mailboxes from 2003 to 2010 ?

Check in your DNS > what does mail resolve to

ping from a workstation to MAIL
it might be pointing to the old exchange 2003

if that is the case, go to your dc

start > run > dnsmgmt.msc

change the a-record for mail to point to the new exchange 2010 lan ip

If you install another CAS temporarily and then forward your OWA/ActiveSync rules to this then it will be able to proxy for both the 2003 server and the 2010 server.

Just don't install the mailbox role.

You need to redirect OWA from exchange 2010 to exchange 2003

Ie. if your user is on exchange 2003 then he will receive above errors.

OWA Configuration
During installation of the Exchange Server 2010 Client Access Server all settings have been configured for use on the Internet. The only thing that needs to be configured is the coexistence information for Outlook Web App. The Client Access Server needs to be configured in case a mailbox is still on Exchange Server 2003 and the client needs to be redirected to the Exchange Server 2003 front-end server.

On an Exchange Server 2010 server enter the following Management Shell Command:

Set-OWAVirtualDirectory <CASHUB01>\OWA ‘
-ExternalURL https://webmail.inframan.nl/OWA ‘
-Exchange2003URL https://legacy.inframan.nl/exchange 

This will make sure that when a user connects to Exchange Server 2010 Client Access Server for Outlook Web Access and the mailbox is still on Exchange 2003 the client will be redirected to the old Exchange Server 2003 front-end server.


refer this it has good exploitation with pictures which show you additional steps on migrate to exchange 2010

http://www.petenetlive.com/KB/Article/0000234.htm
http://msexchangeteam.com/archive/2009/11/20/453272.aspx
http://msexchangeteam.com/archive/2009/12/08/453472.aspx
http://www.petenetlive.com/KB/Article/0000234.htm
http://www.simple-talk.com/sysadmin/exchange/upgrade-exchange-2003-to-exchange-2010/

when a 2003 mailbox user connects to https://mail.yourdomain.com/owa and the cas server detects the mailbox is on 2003 it looks at this attribute to send the request

step 5 from the above link
5.Configure the Exchange 2003 URL property on the /owa virtual directory. This is necessary for Exchange 2003 and Exchange 2010 to coexist. To configure this property, use the following command.

Set-OWAVirtualDirectory <CAS2010>\OWA* -Exchange2003URL https://legacy.contoso.com/exchange 

Note:  
You must enable forms-based authentication on the Exchange 2003 front-end server to allow your users to access their mailboxes through a single sign-on during the coexistence period.

Thanks for all the responses, I will go through in more details them when I get a minute.
I have located the issue related to the old mailboxes that had not yet migrated due to errors, so I have managed to get them across and I can log in now.
I do want to remove the 03 from the network now so this is my next step. I will assign points shortly.
thank you for the responses.