It seems Contact Form 7 is having trouble with accents in checkbox fields.
When using accented characters in values (e.g. [checkbox my-choices use_label_element "région1" "région2"]) the field doesn't display at all in the form.
If replaced with html entities (i.e. [checkbox my-choices use_label_element "r_eacute;gion1" "r_eacute;gion2"]) the field is displayed, but the value won't show in the email. <note: I replaced the & with a _ in here, it seems there's no way to have it show properly otherwise>
With mixed values (i.e. some values with html entities and other with only ascii characters), the ticked option shows up in the email if it is ascii only, not if it contains an html entity.
Is there a way to have accented characters work with a checkbox input at all ? Or maybe a way to differentiate the value and its label ?