paging on list not working

Question

I want to do paging on sharepoint list. I have below code which is giving error.

var customlist;
var allItems;
var context = new SP.ClientContext.get_current();
var web = context.get_web();
var listName = "MyList";
var list = web.get_lists().getByTitle(listName);

var spItems,
    position = null,
    nextPagingInfo,
    previousPagingInfo,
    pageIndex = 1, // default page index value 
    pageSize = 4, // default page size value 
    list,
    camlQuery,
    sortColumn = "Name";
debugger;
camlQuery = new SP.CamlQuery();

camlQuery.set_listItemCollectionPosition(position);

camlQuery.set_viewXml("<View>" +
    "<ViewFields>" +
    "<FieldRef Name='Name'/>" +
    "<FieldRef Name='Email'>" +
    "</ViewFields>" +
    "<Query>" +
    "<OrderBy>" +
    "<FieldRef Name='" + sortColumn + "' Ascending='true' />" +
    "</OrderBy>" +
    "</Query>" +
    "<RowLimit>" + pageSize + "</RowLimit></View>");

spItems = list.getItems(camlQuery);


context.load(spItems, 'Include(Name,Age)');

context.executeQueryAsync(
    Function.createDelegate(this, function () {

        var enumerator = spItems.getEnumerator();

        while (enumerator.moveNext()) {


            var currentListItem = enumerator.get_current();

            var name = currentListItem.get_item('Name');

            var attachments = currentListItem.get_attachmentFiles();
            for (var j = 0; j < attachments.get_count() ; j++) {
                attachment = attachments.getItemAtIndex(j);
                console.log(attachment.get_serverRelativeUrl());


            }

        }
        div.html(innerHtml);

    }),
    Function.createDelegate(this, fail)
);

function fail() {
    debugger;
    alert(arguments[1].get_message());
}

Error is

value doesnt fall within expected range

I think error is coming when i write this line

 camlQuery.set_listItemCollectionPosition(position);

Not sure what to pass in position variable. When I load page for first time what should I pass in position variable?

Update1

If i remove code

camlQuery.set_viewXml("<View>" +
    "<ViewFields>" +
    "<FieldRef Name='Name'/>" +
    "<FieldRef Name='Email'/>" +
    "</ViewFields>" +
    "<Query>" +
    "<OrderBy>" +
    "<FieldRef Name='" + sortColumn + "' Ascending='true' />" +
    "</OrderBy>" +
    "</Query>" +
    "<RowLimit>" + pageSize + "</RowLimit></View>");

and pass hardcoded pagesize then i dont get error

camlQuery.set_viewXml('<View><RowLimit>3</RowLimit></View>');

Update2 Here is list view

Answer 1

your original query has invalid xml, it should be

<FieldRef Name='Email' />

not

<FieldRef Name='Email'>

Answer 2

Declarations

var nextPagingInfo;
var previousPagingInfo;
var position;

Initial call you can make position null, so it starts from the begining

position = null;

//...CAML Query etc
context.load(spItems); 

Now you can invoke the Query using executeQueryAsync. And use below onSuccess

function onSuccess() {   
    var listEnumerator = spItems.getEnumerator(); 
    var items = []; 
    var item; 

    while (listEnumerator.moveNext()) { 
        //Do your logic
    } 
    if (spItems.get_listItemCollectionPosition()) { 
        nextPagingInfo = spItems.get_listItemCollectionPosition().get_pagingInfo(); 
    } else { 
        nextPagingInfo = null; 
    }        
} 

You can retrieve Next page items using

pageIndex++;
if (nextPagingInfo) { 
    position = new SP.ListItemCollectionPosition(); 
    position.set_pagingInfo(nextPagingInfo); 
} 

You can retrieve Previous page items using

pageIndex = pageIndex - 1; 
position = new SP.ListItemCollectionPosition(); 
position.set_pagingInfo(previousPagingInfo);