+ def mime_encode string
+ string = [string].pack('M') # basic quoted-printable
+ string.gsub!(/=\n/,'') # .. remove trailing newline
+ string.gsub!(/_/,'=96') # .. encode underscores
+ string.gsub!(/\?/,'=3F') # .. encode question marks
+ string.gsub!(/ /,'_') # .. translate space to underscores
+ "=?utf-8?q?#{string}?="
+ end
+
+ def mime_encode_subject string
+ return string unless string.match(String::RE_UTF8)
+ mime_encode string
+ end
+
+ RE_ADDRESS = /(.+)( <.*@.*>)/
+
+ # Encode "bælammet mitt <user@example.com>" into
+ # "=?utf-8?q?b=C3=A6lammet_mitt?= <user@example.com>
+ def mime_encode_address string
+ return string unless string.match(String::RE_UTF8)
+ string.sub(RE_ADDRESS) { |match| mime_encode($1) + $2 }
+ end
+