X-MS-Has-Attach: field in interent header RRS feed

  • Question

  • Hi,

    We are trying to block attachments from being sent out using a third party tool. What we were hoping to do was use the

    X-MS-Has-Attach: Yes

    In the internet header as a flag to block the attachment. But what I found that while when the attachment is a .PDF or .Doc file, if the attachment is a .TXT the X-MS-Has-Attach:is blank.

    Any idea's why a .txt file isn't considered an attachment?


    Wednesday, February 6, 2013 2:08 PM


  • Hello,

    You can create a new transport rule:

    When: The email from the third-party tool & the attachment type matches .txt

    Action: Reject the message.


    Simon Wu
    TechNet Community Support

    Friday, February 8, 2013 8:06 AM