TODO

   1
   2 Spec documents:
   3 RFC6530 Overview and Framework for Internationalized Email
   4 RFC5890 Internationalized Domain Names for Applications (IDNA):
   5                 Definitions and Document Framework
   6 RFC6533 Internationalized Delivery Status and Disposition Notifications
   7
   8 - rcpt verification for an internationalized message should require the
   9 destination supports the SMTPUTF8 extension
  10
  11 - transport ditto; nonsupport equates to perm-rej an triggers a bounce
  12
  13 - DSN support extended per rfc 6533
  14
  15 ======================
  16
  17 ++ to-Alabel convert of helo name
  18 ++ - smtp transport
  19
  20 ++ An "international" flag on the message?
  21 ++ An is-international expansion condition?
  22
  23 ++ helo-time option handling
  24 ++ conversion of utf-8 domains for DNS  rfc5890
  25 -- MSA mode: convert on forward?
  26 --- mua-wrapper
  27 --- acl control?
  28
  29 ++ flag in spool file
  30
  31 retries
  32 - apply to a-label or utf8 form?
  33
  34 dsn handling                            rfc6533
  35 - ORCPT param: utf8 vs. unitext encoded
  36 -- to/from unitext expansions ( foo\x{HEXPOINT}  - 2-6 hex digits )
  37
  38 logging
  39 ++ - international msg
  40 - presentation of local-part in log
  41 -- a log option?
  42 encoding of local_part
  43
  44 ++ Recieved-by header tracking info
  45 ++ - WITH protocol types get UTF8 prefix
  46 ++ - use for logging also
  47
  48 forwarding checks                       rfc6530 7.1 -3-
  49 - rcpt-time rejects get 533 mailbox name not allowed
  50 - mail-time rejects get 550 mailbox unavailable
  51 - bounces (see dsn handling)
  52
  53 ++ expansions for to- and from-Alabel ? bug1567
  54
  55 enhanced status codes?                  rfc5248++
  56
  57 VRFY
  58 EXPN
  59
  60 non-smtp input