Hi Daniel,
We had a look into the issue, which seems to be with String based attachments.
We've added a fix to the Mandrill plugin: plugins/system/mandrill/mailer/mail.php, line 617:
// check for string attachment
if($attachment[5]) {
$attachmentContent = $this->EncodeString($attachment[0]);
} else {
$attachmentContent = $this->EncodeFile($attachment[0]);
}
if (preg_match('/^image/', $mime_type))
{
// Image attachment
$iAttachments[] = array(
'name' => $attachment[2],
'type' => $mime_type,
'content' => $attachmentContent
);
}
else
{
// Normall attachment
$mAttachments[] = array(
'name' => $attachment[2],
'type' => $mime_type,
'content' => $attachmentContent
);
}