This property contains the headers for each MIME part.
def get_part_headers(part_idx: int) -> str: ... def set_part_headers(part_idx: int, value: str) -> None: ...
This property contains the headers for each MIME part. The class fills out this property each time any of the other corresponding Part- properties is changed. If additional headers are needed, they should be appended after all the other corresponding Part- properties are set.
The part_idx parameter specifies the index of the item in the array. The size of the array is controlled by the part_count property.