After sending an email from Outlook 2011, it will occasionally be received in garbled Chinese.  The user will type out their message, hit Send, and it will appear as if he had sent it in Chinese when it arrives at the recipients' inbox.  When the user reviews the email in his Sent folder, he can see that the email appears in Chinese as well.  I believe it's isolated to Outlook 2011 because the email appears in English everywhere else, and in fact, his signature appears in English as normal.  The user does not speak Chinese, and does not have any multi-language functionality enabled on his Mac.  Our mail service is run through an Office 365 server.  An example of the text can be shown here:

取・貍取縺箴鹿蒹痲昭硼糯ﾀ繽A・鰾∠鱇雕ﾀ琺聶窮苓停ｹﾀｫ・硅蜚㍽碵隲迴粤込齔痺綮ﾀｫ・硅蜚㈹蜴絖碣縺觝ﾀﾟ胄纈∠蓍・∮鞜竇・竢跫鮑ﾀｄｮ・穐ﾀｮ・

Translated using an online service, it reads: Take · Beaver take Lian Zhen Lu Jian Ma Chao boron waxy Tatari  Bean A · bladder ∠ angler carved Tatari enamel Nie poor Ling stopped ke taォ· silicon enjoys ㍽ Tian Zhi in Guangdong includes the postage milk teeth numb the mark Tatariォ· silicon enjoys ㈹ chameleon Kuang Gar Lian butt Tatari゚helmet Valerian ∠ Achillea · ∮ ta ta Dou Bao Si trampling dョョ· ta · Qiu

Obviously this is just gibberish.  Is it possible that his text's formatting is being misinterpreted by the Office 365 server?  If so, what would be a good method to reliably prevent this issue from arising in the future?