Znarkus/postmark-php — pull request #12 by plusbryan (2011-11-09 16:11:50+00:00)
Title: international support: encode non-utf8 strings for compatibility with json_encode

A fix for:

Error Message:
json_encode(): Invalid UTF-8 sequence in argument

Where:
postmark.php, line 326

Since json_encode does not support non-utf8 strings (example: ถ.พิทักษ์), it was throwing this error when trying to send email containing non-utf8 strings. This fix utf8 encodes the strings before passing them to json_encode.