Hi,I deployed an exchange server in two of our branch offices it is looks like that:first site:one server has - CAS - HUB - UMone server has - Mailbox serversecond site:one server has - CAS - HUB - UMone server has - Mailbox servernote that the first site is connected to the public internet to send and get the emails.I enabled the across site proxying for pop to let it work from anywhere and to point it to one domain name which is the CAS server in site one.The problem is that the users that have the mailboxes in second sitethey cannot get the pop connectivity it is showing an error when they trying to sync.I test pop connectivity from CAS server the first site and it is giving this errornow the problem Im facing is that when a user in second and his mail box in the second site also when he is trying to connect using pop3 and pointing the server in first site:the command that i tried is:Test-PopConnectivity -ClientAccessServer <Cas saerver in the second site>the out put was:Test-PopConnectivity : MapiExceptionNetworkError: Unable to make admin interface connection to server. (hr=0x80040115, ec=-2147221227)Diagnostic context: ...... Lid: 13720 dwParam: 0x6BA Msg: EEInfo: Flags: 0 Lid: 11672 dwParam: 0x6BA Msg: EEInfo: NumberOfParameters: 0 Lid: 16280 dwParam: 0x6BA Msg: EEInfo: ComputerName: n/a Lid: 8600 dwParam: 0x6BA Msg: EEInfo: ProcessID: 884 Lid: 12696 dwParam: 0x6BA Msg: EEInfo: Generation Time: 2009-11-04 06:41:39:317 Lid: 10648 dwParam: 0x6BA Msg: EEInfo: Generating component: 8 Lid: 14744 dwParam: 0x6BA Msg: EEInfo: Status: 11001 Lid: 9624 dwParam: 0x6BA Msg: EEInfo: Detection location: 320 Lid: 13720 dwParam: 0x6BA Msg: EEInfo: Flags: 0 Lid: 11672 dwParam: 0x6BA Msg: EEInfo: NumberOfParameters: 1 Lid: 8856 dwParam: 0x6BA Msg: EEInfo: prm[0]: Unicode string: HQMBX01 Lid: 24060 StoreEc: 0x80040115 Lid: 23746 Lid: 31938 StoreEc: 0x80040115 Lid: 19650 Lid: 27842 StoreEc: 0x80040115 Lid: 20866 Lid: 29058 StoreEc: 0x80040115At line:1 char:21+ Test-PopConnectivity <<<< -ClientAccessServer hqht01 |fl when i'm running the command from the second site CAS server it works fine.Could any one help me in this problem please..

See this post and i can see the problem got resolvedhttp://social.technet.microsoft.com/Forums/en/exchangesvrmigration/thread/df1cb9c6-251b-4e48-b17a-216444d484b7Raj

Hi,Did you like to proxy the POP3 request between the CAS in different site? If that is your need, please understand that proxying for POP3 and IMAP4 is not supported.For the information, pleaserefer tothe below article:http://msexchangeteam.com/archive/2007/09/04/446918.aspxHowever, this feature is supported in the Exchange 2010. Maybe you can wait for this to be released.ThanksAllen