Getting SPUser object from "Group or People" SPListItem field

Question

I am using a Powershell and CAML query to return items from a list. The list contains a "Group or People" field in which I have not seeing how to get the email and login information of the user. I assume I need to cast it to a SPUser object but have been unsuccessful so far. Anyone have an approach or snippet use?

$spQuery = New-Object Microsoft.SharePoint.SPQuery
$camlQuery = "<Where>...</Where>"
$spQuery.Query = $camlQuery;

$spListItems = $spList.GetItems($spQuery);

$spListItems |  Sort-Object Title | ForEach-Object -Process {

$spListItem[4]; # this returns display name only 

}

Answer 1

With the help of this blog I found the answer. http://codingmode.com/category/uncategorized/

replace:

$spListItem[4]

with:

Get-UserEmail($spListItem.Fields[4].GetFieldValue($spListItem[4].ToString()))

add this function:

function Get-UserEmail([Microsoft.SharePoint.SPFieldUserValue]$SPFieldUserValue)
{
    $isNull = [String]::IsNullOrEmpty($SPFieldUserValue);
    if($isNull -eq $false){
        return $SPFieldUserValue.User.Email;
    }
    return $isNull;
}

Answer 2

$personFieldValue = $ListItem["PersonFieldName"].ToString();            
$spFieldUserValue = New-Object Microsoft.SharePoint.SPFieldUserValue($oWeb,$personFieldValue);