If you are creating a custom email from scratch then use the following code in your header, which will ensure that characters with accents are correctly handled through the email client.
Make sure you define headers and body text which is standard practice, so is defining the HTML type and content type.
This to start:
<html><head><!DOCTYPE html PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”><meta content=”text/html; charset=utf-8″ http-equiv=Content-Type></head><body><p><b><font size=”5″ face=”Verdana”>
And this to finish:
If accented characters do not display correctly then use charset=iso-8859-1 instead of utf-8 or the appropriate charset for your language – see Wiki for further details.