Default coding system ?

[François Fleuret]

Hi,

I read my mail with gnus, and from time to time, especially with spam
mails, gnus asks for a coding system with the following warning

,----
| These default coding systems were tried to encode text
| in the buffer ` *temp*':
|   iso-latin-1
| However, each of them encountered these problematic characters:
|   iso-latin-1: � � � � � � � � � � ...
| The first problematic character is at point in the displayed buffer,
| and C-u C-x = will give information about it.
| 
| Select one of the following safe coding systems, or edit the buffer:
|   utf-8
| Or specify any other coding system
| on your risk of losing the problematic characters.
`----

I looked for a list of default coding systems with apropos-value
"iso-latin-1" but could not figure what list to change ... And this
coding system issue is such a mess that I can not find the courage to
go deeper in the documentations.

Any idea ?

Thanks in advance,

-- 
François Fleuret