def remove_initial_spaces_and_mark_message_lines(lines):
    """
    Removes the initial spaces in each line before marking message lines.

    This ensures headers can be identified if they are indented with spaces.
    """
    i = 0
    while i < len(lines):
        lines[i] = lines[i].lstrip(' ')
        i += 1
    return mark_message_lines(lines)
Removes the initial spaces in each line before marking message lines.

    This ensures headers can be identified if they are indented with spaces.