EV 10.0.3 Client - Unable to find Exchange Server

Hello

I know there're multiple forums or articles where user or particular organization reports that EV client on Macintosh generates error upon login which states that "Unable to connect to Exchange Server", but none have helped so far in our particular scenario:

Environment

1. Server - Enterprise vault 9.0.4 CU3
2. Client - Enterprise vault 10.0.3
3. Macintosh OS - 10.7
4. Outlook 2011 - 14.0.4

Issue: I've read at couple places that for Macintosh client to work, the backend EV server should also be version 10 and above. However, just wondering if someone can double confirm for me please and point to any particular technote/page on compatibility guide where it says so, so I can provide to our user as proof accordingly.

Meanwhile, the EV client on Macintosh system seems to be fetching exchange URL and login details correctly at first place, however down the log, I see below lines:

2013-06-01 03:22:20 +0000 : Status Code = 440
2013-06-01 03:22:20 +0000 : Exiting - [Http sendSynchronousRequestWith:method:contentData:forUser:numOfRetries:httpStatusCode:error:]
2013-06-01 03:22:20 +0000 : Exiting - [Http sendSynchronousRequestWith:method:contentData:forUser:error:]
2013-06-01 03:22:20 +0000 : Unable to create XML Document from response
2013-06-01 03:22:20 +0000 : Exiting - [ExchangeServer getInboxURI:]
2013-06-01 03:22:20 +0000 : Exiting desktop setting from Exchange 2007
2013-06-01 03:22:20 +0000 : Entering desktop setting for Exchange 2003
2013-06-01 03:22:20 +0000 : URL given by Entourage is wrong so guessing the URL !!!
2013-06-01 03:22:20 +0000 : Entering - [ExchangeServer getInboxURI:]

2013-06-01 03:26:23 +0000 : Exiting - [Http performRequest:]
2013-06-01 03:26:23 +0000 : Status Code = 0
2013-06-01 03:26:23 +0000 : Exiting - [Http sendSynchronousRequestWith:method:contentData:forUser:numOfRetries:httpStatusCode:error:]
2013-06-01 03:26:23 +0000 : Exiting - [Http sendSynchronousRequestWith:method:contentData:forUser:error:]
2013-06-01 03:26:23 +0000 : No response from Server.
2013-06-01 03:26:23 +0000 : Exiting - [ExchangeServer getInboxURI:]
2013-06-01 03:26:23 +0000 : Unable to retrieve inbox URI from server so trying with a different URL  !!!

2013-06-01 03:28:23 +0000 : Exiting - [Http performRequest:]
2013-06-01 03:28:23 +0000 : Redirection, retrying with new url redirectionCount = 0
2013-06-01 03:28:23 +0000 : New Redirection URL is https://email.contoso.com/owa/dduck
2013-06-01 03:28:23 +0000 : Entering - [Http createRequestWith:method:contentData:]

I see log lines before same where it has got correct URL to EWS which is https://email.contoso.com/EWS/Exchange.asmx, but I am not sure why it reports that URL is wrong and it has to start guessing random URLs after same.

Any particular configuration setting or desktop policy or modifcation in web.config file that I can make so it'll stop guessing and connect to correct URL please? OR any other suggestions in this direction.

EWS and Autodiscovery on Exchange 2010 side works fine, that has been validated accordingly.

Thank You !