Microsoft Mobile Push Doesn’t Work With ISA 2000

According to this post by Daniel Melanchthon Mobile Push mail that is coming with Windows Mobile 5 may not work out of the box on Microsoft Exchange 2003 SP2 if ISA 2000 is installed (which particularly also affects SBS 2003). Here is the thing, ActiveSync negotiates Push with the server by checking if its even available. According to Amy Babinchak, if ISA 2000 is installed by default it does not pass OPTIONS it does not know to the published server. Since Outlook Mobile Admin resides on the Front End server of Exchange 2003 SP2 deployment (or just the SBS server) request for options would pass this back: =-=-=-= Server Response =-=-=- HTTP/1.1 200 OK Content-Length: 136 Date: Mon, 30 Jan 2006 19:30:13 GMT Content-Type: application/vnd.ms-sync.wbxml Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET Pragma: no-cache MS-Server-ActiveSync: 6.5.7638.1 Effectively, push mail will not work with Exchange 2003 SP2/SBS & ISA 2000 installed without adding the following registry key: HKLM\System\CurrentControlSet\Services\W3Proxy\Parameters Value Name: PassOPTIONSToPublishedServer After it is added the OPTIONS keyword goes to the Exchange server which hopefully produces the following response: =-=-=-= Server Response =-=-=- HTTP/1.1 200 OK Date: Fri, 13 Jan 2006 14:13:41 GMT Server: Microsoft-IIS/6.0 X-Powered-By: ASP.NET Pragma: no-cache Content-Length: 0 Public: OPTIONS, POST Allow: OPTIONS, POST MS-Server-ActiveSync: 6.5.7638.1 MS-ASProtocolVersions: 1.0,2.0,2.1,2.5 MS-ASProtocolCommands: Sync, SendMail, SmartForward, SmartReply, GetAttachment, GetHierarchy, CreateCollection, DeleteCollection, MoveCollection, FolderSync, FolderCreate, FolderDelete, FolderUpdate, MoveItems, GetItemEstimate, MeetingResponse, ResolveRecipients, ValidateCert, Provision, Search, Notify, Ping Now please remember that this applies to ISA 2000, not 2004. I am obligated to say this again to limit the comment outrage: There is still NO device on the US market that has Microsoft Mobility & Security Feature Pack (Push Mail) available.