TYPO3 Core

Having the following form the subjectField does not seem to work. I.e. the subjectField is not respected.

enctype = multipart/form-data
method = post
confirmation = 1
prefix = standardForm
class = standardForm

postProcessor {
    1 = mail
    1 {
        senderEmailField = email
        senderNameField = surname
        subjectField = subject
        recipientEmail = mail@example.com
        priority = 1
        organization = TRITUM
    }
}

10 = TEXTLINE
10 {
    name = surname
    label = Surname
}

20 = TEXTLINE
20 {
    name = email
    label = Email
}

30 = TEXTLINE
30 {
    name = subject
    label = Subject
}

100 = SUBMIT
100 {
    name = submit
    value = Submit
}