I'd like to use PHPMailer <http://phpmailer.sourceforge.net/> to send
out e-mail messages in Chinese, Korean, Japanese and Russian. The
messages are auto-generated and personalized using an HTML form on a
web site.

However I've got some problems encoding these double-byte charsets so
that the messages arrive correctly at their destination.

Currently, I'm only sending out an English version of the messages as
I can't send double-bytes messages.

You can see the web forms at:

http://www.lovecalculator.be/zh/create.php
http://www.lovecalculator.be/ko/create.php
http://www.lovecalculator.be/ja/create.php
http://www.lovecalculator.be/ru/create.php

Which encoding and which character sets should I use so that the
messages show up correctly in the e-mail programs and webmail systems
used in those languages?

Possible encodings in PHPMailer are: 8bit, 7bit, binary, base64 and
quoted-printable

I'm not sure about the character-sets for the messages. The subjects
of the messages should also be encoded. I was hoping that UTF-8 would
work, however UTF-8 messages are not displayed correctly on Hotmail
and some other web mail systems.

If plain text messages don't work correctly at all, then I wouldn't
mind if the messages are sent as HTML although some e-mail programs
will have problems with it as long as the double-byte character sets
are displayed correctly and the user can read the message without any
problems.

Some server information:
OS: MacOS X Server 10.4.8
HTTP Server: Apache 2.2.x
Programming language: PHP 5.1.x
Database: MySQL 5.0.x

Thank you for your time and help.