Fetching user names and E-mail Addresses from SPGroups

There are various groups present over a SharePoint Site. The below code can extract email addresses of all the existing users in all the groups.

Code to get the user names:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{

string username;

SPSite spsite = new SPSite("site url"); //Ex: http://adfsaccount:2222/
SPWeb web= spsite.RootWeb;
SPUserCollection userlist= web.AllUsers;
foreach (SPUser u in userlist)
{
username=u.Name;
}
}
}
}

Code to get the email addresses:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{

SPSite spsite = new SPSite("site url"); //Ex: http://adfsaccount:2222/
SPWeb web= spsite.RootWeb;
SPUserCollection userlist= web.AllUsers;
foreach (SPUser u in userlist)
{

string email = u.Email.ToString();
}

}
}
}