Exchange 2010 / 2013 Coexistence.

I have 2013 installed. Tested access to mailbox sitting on 2013 using OWA and Outlook client(using host file pointed to 2013 to test). Connection works. Emails flowing between mailboxes in 2010 and 2013.

Before moving mailboxes wanted to test redirection/proxy for mailboxes still on 2010. Using OWA on 2013 trying to access mailbox still on 2010, able to login but getting message: can't get info right now, try again later. Reversed process accessing 2013 mailbox from OWA 2010 also gives an error: server config temporarily preventing access to your account.

Client connection redirection does not seem to work between 2010 & 2013. Might be missing configuration/setting to allow/accept connections between servers??

Hi Andy,
Did you try after making the authentication of Owa's 2010 set to Windows Authentication?
If not please try that.

After moving mailbox please give some time to replicate the changes and try to access OWA2013.

Hello,

To configure the proxy or redirection, please make sure:

1. Use Exchange 2013 as the Internet facing server.

2. Configure the internalurl on the CAS 2010 and set to itself (proxy)

3. Configure the externalurl on the CAS 2010 and set it to the 2010 public url (Redirection)

https://technet.microsoft.com/en-us/library/bb310763(v=exchg.141).aspx

Thanks,

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