Try
@Html.EditorFor(x => x.Emails, "string", "EmailAddress") //or EmailAdress
MSDN reference has the following, you are interested in the htmlFieldName
public static MvcHtmlString EditorFor<TModel, TValue>(
this HtmlHelper<TModel> html,
Expression<Func<TModel, TValue>> expression,
string templateName,
string htmlFieldName
)
A string that is used to disambiguate the names of HTML input elements that are rendered for properties that have the same name.
To edit the prefix you can set this in your controller
ViewData.TemplateInfo.HtmlFieldPrefix
or in your view
@Html.ViewContext.ViewData.TemplateInfo.HtmlFieldPrefix = "Foo"
Of course you could write your own helper that does this wherever you use it.