Before you start making additions to mailx, subscribe to the development
mailing list at <https://lists.sourceforge.net/lists/listinfo/nail-devel>
to coordinate your efforts with the maintainer and other people.

------------------------------------------------------------------------
The following features are missing for conformance with the Single Unix
Specification, v.3:

* LC_TIME environment. This conflicts with the mail RFCs and historical
  usage. It was optional POSIX.2, but the newer standards mention this
  in the rationale only. Won't be implemented here.

* onehop variable (not demanded by POSIX standards). Seems absolutely
  obsolete. If anybody has a need for it, he should contribute code.

------------------------------------------------------------------------
The following IMAP features could be implemented in the future. If you
need them and cannot wait, contribute code.

- The MIME capabilities of IMAP could be used so that not entire messages
  are downloaded all the time, but just the parts that are actually needed.

- SASL authentication methods could be implemented.

- The deletion code (more general, all STORE code) should be able to
  generate requests for ranges of messages to speed up operation.

- Large messages should be transferred in separate parts with IMAP so
  that the operation can be interrupted in between.

------------------------------------------------------------------------

The POP3 client supports USER/PASS and APOP authentications only. If you
need other authentication methods and have the ability to test them,
please write and contribute code.

A variable should be added to specify the default character set for
messages without MIME declarations.

If you want to edit arbitrary header fields with the 'editheaders'
option, you are invited to supply code for it. Be warned that this
is a nontrivial task due to MIME. Contact the development mailing
list before you start coding.

Several people have suggested adding support for arrow keys at the
command prompt, autocompletion for attachment filenames, etc. I am
personally not going to implement this as X Window Copy-and-Paste
satisfies me. But if you desparately need it, you're invited to
contribute code. You can't use libreadline, though, because its
license is incompatible, and I insist that your implementation
is done in a way that a) mailx can still be compiled without
requiring any further libraries (i. e. your code is optional)
and b) your code works for all kinds of terminals, not just
VT100/ANSI ones.

Mailx will not support 'Return-Receipt-To' or 'Disposition-Notification-To'
header fields, neither for the sending nor for the receiving part.
For the sending part it plainly doesn't work because one wants to
know whether the human recipient has read the mail and not if he
clicked on some send-a-receipt-button while looking out of the
window. For the receiving part, it is simply annoying. If you want
a confirmation, ask the recipient to send one in the body of the
message.

	Gunnar Ritter					3/4/06
