[imp] IMP message Charset

[Gian Marco Fenu]

Hi all, I see that my imp installation use charset UTF-8; some of my 
users read mails using ISO-8859-15 and so see strange characters on 
incoming mails... It is not graceful so I decided to let horde imp use 
ISO-8859-15 too... To do so I edited /horde/config/nls.php in this way:

$nls['defaults']['language'] = 'it_IT';
$nls['defaults']['charset'] = 'ISO-8859-15';

I though it was the right way, but messages are still sent using UTF-8...

Anyone can help me to let horde imp use ISO-8859-15 or 8859-1 for 
compose messages?

Thanks.
Gian Marco Fenu