Yes as long as you set the charset correctly for sending email and have the most current version of autoresponder. You can set the charset by going to the email setup.
Can I use one autoresponder for multiple languages or do I have to set up another autoresponder for another language, such as Japanese? then Chinese? Then Thai?
The charset is for all of one installation of autoresponder, so you could not send out emails with different charsets in one installation of autoresponder.