When you receive an IM while offline with "send offline IM to email" turned on, you get an email containing the IM from a specially formatted email address. You can reply to this IM and your email is sent as an IM response in-world. However, unicode characters are not handled properly by the email to IM gateway. As far as I can tell, emails containing unicode are sent with the entire body encoded in base64. A content-encoding header in the email alerts an email client that the message is in base64, and that the data is in UTF-8. LL's IM to email gateway cannot decode these messages and silently drops them on the floor, as far as I can tell. Trying to send unicode characters directly in a plain IM fails as well. Non-ascii characters show up as ?'s in the IM. This probably makes the reply mechanism useless for chinese speakers and others whose emails cannot be transliterated well into English characters.