I am sending an HTML e-mail via API whichi s UTF-8, however Mailgun seems to sometime use base64/UTF-8 and sometimes use quoted-printable ascii.
I am having a problem with Outlook 2013 (incorrectly I believe) re-writing the header of the HTML e-mail from UTF-8 to ascii and then not displaying my pound sign: £ as it doesn't exist in ascii.
I suspect this is happening in Outlook 2013 becuase the character encoding of the mime part is ascii and the e-mail is UTF-8. I believe the only way to get round this is to force Mailgun to send the e-mail using base64 mime encoding and UTF-8 but I don't know how to force that to happen using the API.
