As well as Printable ASCII, EML supports the Latin-1 Supplement.
Some reading indicates that ASCII and Latin-1 together can handle the following languages: Afrikaans, Basque, Catalan, Danish, Dutch, English, Faroese, Finnish, French, Galician, German, Icelandic, Irish, Italian, Norwegian, Portuguese, Spanish and Swedish. Note: Some rare characters (e.g. the capital Y with an umlaut in French) are not handled.
Example of using Latin-1 in EML:
<latin-1>h_e'l_l_o_</latin-1> will be rendered as: héllo
Please see the following article for further details.
Edgecase Markup Language (EML): Latin-1