SMTP (simple mail transfer protocol), which is the key behind e-mail communication, was NOT designed to handle modern complication of encoding/charset issues. Therefore, a lot of the e-mail gateways out there will simply truncate the 8th bit of each byte in your message, producing nonsense thereafter.
Whichever e-mail client that you are using, try to check your e-mail's encoding (not the encoding that you typed in), and set it to "quoted printable," which is most accessible if both parties are based on Windows OS.
