Try this:
var user = web.SiteUsers.GetById(usvSM1.LookupId);
context.Load(user);
context.ExecuteQuery();
Console.WriteLine(user.Email);
EDIT: Web.SiteUsers property is available only SharePoint 2013 client object model.
Second way you can try to get user:
var user = web.EnsureUser(usvSM1.LookupValue);
context.Load(user);
context.ExecuteQuery();
Console.WriteLine(user.Email);