Windows 10 Mailslots RRS feed

  • Question

  • Hi,

    I know there is an issue where Windows 10 update 1803 requires mailslots to send via broadcast as opposed to specifying the target machine name in the open command.

    Ok, there is a patch in a newer build SDK that I don't have, but that's beside the point.

    Anyway, I changed the code and it runs just fine on 5 Windows 10 platforms with 1803 patch.

    But it doesn't work on a 6th!!!

    It didn't work before applying 1803.

    I can do all the other networky stuff - browse, open, close, read, write, delete, …..

    But there is some "setting" that is stopping mailslots cold.

    sample code:


      wsprintf( targname, "\\\\*\\mailslot\\%s\\dbecvrs", acGatewayName );
       msht = CreateFile( targname, // name of the file
                          (DWORD)GENERIC_WRITE, // access (read-write) mode
                          (DWORD)FILE_SHARE_READ|FILE_SHARE_WRITE, // share mode
                          (LPSECURITY_ATTRIBUTES)NULL, // security descriptor
                          (DWORD)OPEN_ALWAYS, // how to create
                          (DWORD)FILE_ATTRIBUTE_NORMAL, // file attributes
                          (HANDLE)NULL );  // handle of file with attributes to copy


    Works on 5 macines, fails on one.

    There is no error indication, the open, read, write all complete indicating success, but obviously not.

    Is there some "Local Security Policy" I need to set or some similar feature?

    Please advise.



    Tuesday, September 11, 2018 6:57 PM