class Mail::Encodings::SevenBit

7bit and 8bit are equivalent. 7bit encoding is for text only.

def self.compatible_input?(str)

Per RFC 2045 2.7. 7bit Data, No octets with decimal values greater than 127 are allowed. 
def self.compatible_input?(str)
  str.ascii_only? && super
end

def self.decode(str) 

def self.decode(str)
  ::Mail::Utilities.binary_unsafe_to_lf str
end

def self.encode(str) 

def self.encode(str)
  ::Mail::Utilities.binary_unsafe_to_crlf str
end