MIME content headers syntax for attachment name RRS feed

  • Question

  • Hello, 

    I've the following problem: an application sends a MIME text mail with text/plain attachments with the following syntax. Some recipients see the attachment as attachment, others see the attachment included in the body of the message. I noticed that adding the string ' ; filename="5823751_FILE.txt" ' in the Content-Disposition or Content-Type headers resolves the problem.

    My question is: IS adding the filename= field mandatory by RFC ?

    Content-Type: multipart/mixed; boundary="SAP.Boundary.1819UUeyeELesOHenNhOj"

    Content-ID: <SAPOffice.1>
    Content-Description: TEST MAIL [1 attachments]
    Content-Type: text/plain; charset="US-ASCII"
    Content-Transfer-Encoding: 7BIT

    Content-ID: <SAPOffice.2>
    Content-Description: 5823751_FILE.txt

    Content-Type: text/plain; charset="ISO-8859-1"
    Content-Transfer-Encoding: QUOTED-PRINTABLE

         <attachment text removed>


    Wednesday, January 9, 2013 5:16 PM