Dexim4 port 25 sends e-mail with ANSI charset

I have installed a JSP script that used to send e-mail fine. My e-mail messages needs to be in Portuguese. I use UTF-8. I just got a linode and configured Dexim4 to send e-mail from the localhost, but I see the acent characters are wrong. When I looked in the e-mail message plain text I saw that the charset is wrong:

Would you know how I configure Dexim to send always as UTF-8? Does it make sense to do this way? Looks like when I try to pass UTF-8 from the JSP, javax mail interfaces, Dexim is ignoring - not sure why the JSP cannot pick the charset / or pass the desired charset.

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Subject: =?ANSIX3.4-1968?Q?LPEU-D=3Fvidaenviadapelosite?=

Mime-Version: 1.0

Content-Type: text/plain; charset=ANSI_X3.4-1968

Content-Transfer-Encoding: 7bit