Strategy for handling non-ASCII with Mail

asciiify.rb

# Escape non-ASCII characters and forward slashes as unicode escape sequences,
# but with forward slashes instead of backslashes, since backslashes already have meaning
def asciiify(str)
  str.unpack('U*').map { |i|
    (i == 47 || i == 92 || i > 127) ? "/u" + i.to_s(16).rjust(4, '0') : i.chr
  }.join
end

# Decode "forward slashed" unicode escape sequences
def deasciiify(str)
  str.gsub(/\/u([\da-fA-F]{4})/) { |m|
    [$1].pack("H*").unpack("n*").pack("U*")
  }
end

raw = "Abé Allen <a@a.com>, 粗楷体简 <b@b.com>, c@c.com, //// <hi@hi.com>"
list = Mail::AddressList.new(asciiify(raw))
puts deasciiify(list.addresses[1].format) # 粗楷体简 <b@b.com>