Prior to the bug fix, when sending a mass email initiation, if the message contained foreign language characters, the campaign would only be sent if the message was sent as a Plain-Text-only or an HTML-only email. If both MIME parts, Plain Text and HTML, were included, then the email campaign would error out.
Screenshot of a mass email initiation composed using Outlook Express, and the message contains Chinese characters. Outlook Express will send this with both Plain Text and HTML parts.
A mass email initiation is an email campaign triggered from a desktop or other email client outside of JangoMail. For example, you can use Outlook, GMail, or Thunderbird to compose an email campaign, send it to your assigned @init.jangomail.com email address, and then have JangoMail send the campaign to your email list. For more information on this feature, see this tutorial.