History of sender's email and recipent's email ?

Jer,

So this is the document you mentionned :

<?php // $Id: send.module,v 1.33 2007/12/07 19:45:24 vauxia Exp

/** 
 * @file
 * A "send this page" module with crm integration and a history of sent items
 * 
 */
 
/**
 * Implementation of hook_perm().
 */
function send_perm() {
  return array('administer send', 'send nodes', 'view send statistics');
}

/**
 * Implementation of hook_menu().
 */
function send_menu($may_cache) {
  global $user;
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path'         => 'send', 
      'title'        => t('Send'), 
      'callback'     => '_send', 
      'callback arguments' => array('page'), 
      'access'       => user_access('send nodes'),
      'type'         => MENU_SUGGESTED_ITEM,
    );
    $items[] = array(
      'path'         => 'admin/content/send', 
      'title'        => t('Send modules'), 
      'callback'     => 'drupal_get_form', 
      'callback arguments' => array('_send', 'module_form'), 
      'description' => t('Default settings for "Send to Friend" and other modules that send content via e-mail'),
      'access'       => user_access('administer send'),
      'type'         => MENU_NORMAL_ITEM,
    );
    $items[] = array(
      'path'         => 'admin/content/send/default',
      'title'        => t('Defaults'),
      'callback'     => 'drupal_get_form', 
      'callback arguments' => array('_send', 'module_form'), 
      'access'       => user_access('administer send'),
      'type'         => MENU_DEFAULT_LOCAL_TASK,
      'weight'       => -10,
    );
    foreach (send_modules() as $module => $name) {
      $items[] = array(
        'path'     => 'admin/content/send/'. $module, 
        'title'    => module_invoke($module, 'send', 'name', $module),
        'callback'     => 'drupal_get_form', 
        'callback arguments' => array('_send', 'module_form', $module), 
        'access'   => user_access('administer send'),
        'type'     => MENU_LOCAL_TASK,
      );
    }
  }
  else {
    // Hide the views-generated send statistics tab on each node page.
    // We can't do this from views' access controls because it depends on both
    // the user's permissions and the node's type.
    if (arg(0) == 'node' && is_numeric(arg(1))) {
      $path = 'node/'. arg(1) .'/send';

      if (!user_access('view send statistics')) {
        // Manually hide the statistics tab if user has no access to statistics.
        $items[] = array('path' => $path, 'access' => false);
      }
      else {
        // Manually hide the statistics tab if it's a no-op for this node type.
        $node = node_load(arg(1));
        $access = false;
        foreach (send_modules() as $m => $name) {
          if (variable_get("{$m}_{$node->type}", 0)) {
            $access = true;
            break;
          }
        }
        if ($access == false ) {
          $items[] = array('path' => $path, 'access' => false);
        }
      }
    }
  }
  return $items;
}
/**
 * Implementation of hook_nodeapi().
 */
function send_nodeapi(&$node, $op) {
  switch ($op) {
    case 'insert':
    case 'update':
      return _send('settings_submit', $op, (array)$node);
    case 'delete':
      return db_query("DELETE FROM {send_setting} WHERE nid = %d", $node->nid);
  }
}

/**
 * Implementation of hook_user().
 */
function send_user($op, &$edit, &$user) {
  switch ($op) {
    
    case 'insert' :
      //if user has been a recipient before, note their uid
      if (!$user->mail) return;
      db_query("UPDATE {send} SET uid = %d WHERE mail = '%s'", $user->uid, $user->mail);
      db_query("UPDATE {send_recipient} SET rid = %d WHERE mail = '%s' AND rtype='user'", $user->uid, $user->mail);
      return;
      
    case 'delete':
      // no orphan uids
      db_query("UPDATE {send} SET uid = 0 WHERE uid = %d", $user->uid);
      db_query("UPDATE {send_recipient} SET rid = 0 WHERE rid = %d AND rtype='user'", $user->uid);
      return;
  }
}

/**
 * Implementation of hook_form_alter()
 */
function send_form_alter($form_id, &$form) {
  switch ($form['#id']) {

    case 'node-type-form':
      $form = _send('nodetype_form', $form);
      return;
      
    case 'node-form':
      $form = _send('node_form', $form);
      return;
  }
  return;
}

/**
 * Implementation of hook_link().
 */
function send_link($type, $node=null) {
  if (!$node) return;
  
  foreach (send_modules() as $m => $name) {
    if (variable_get("{$m}_{$node->type}", 0) && module_invoke($m, 'send', 'access', $m)) {
      if (variable_get("{$m}_{$node->type}_pernode", 0)) {
        $linktext = _send('value', 'linktext', $m, $node->type, $node);
      }
      else {
        $linktext = variable_get("{$m}_{$node->type}_linktext", '');
      }
      if ($linktext) {
        $links[$m] = array(
          'title' => t($linktext),
          'href'  => "send/{$m}/{$node->nid}",
          'attributes' =>  array("class" => 'send-link send-'. $m)
        );
      }
    }
  }
  return $links;
}

/* Implementation of hooks for the views module
 */
function send_views_pre_query() {
  require_once dirname(__FILE__) .'/send_views.inc';
}

function send_views_tables() {
  require_once dirname(__FILE__) .'/send_views.inc';
  return _send_views_tables();
}

function send_views_arguments() {
  require_once dirname(__FILE__) .'/send_views.inc';
  return _send_views_arguments();
}

function send_views_default_views() {
  require_once dirname(__FILE__) .'/send_views.inc';
  return _send_views_default_views();
}

/**
 * Implementation of our own send hook
 */
function send_send($op, $module = 'send', $nodetype='', $node=null) {
  if ($node) { 
    $nodetype = $node->type;
  } 
  if ($nodetype) {
    $nodename = node_get_types('name', $nodetype);
  }
  
  switch ($op) {
    case 'name':                 // human readable name of the module
      return t('Send to Friend');
      
    case 'features':             // features that this module uses
      return array('send', 'block');
      
    case 'access':               // access control for this module
      return user_access('send nodes');
      
    case 'settings':             // settings form
      return;
      
    case 'subject':              // default setting for subject line
      if ($module == 'send' && $nodename) {   
        return t('@name from '. variable_get('site_name', 'Drupal'), array('@name' => $nodename));
      }
      if ($name = module_invoke($module, 'send', 'name', $module)) {
        return t('@name from '. variable_get('site_name', 'Drupal'), array('@name' => $name));
      }
      return;
      
    case 'message':              // default message text
      return;
      
    case 'template':             // template/layout
      return theme('send_template');
      
    case 'linktext':             // default setting for link text
      if ($module == 'send') return t('send to friend');
      if ($name = module_invoke($module, 'send', 'name', $module)) {
        return strtolower(t('send @name', array('@name' => $name)));
      }
      return;
      
    case 'threshold':            // default setting for send threshold
      return 10;
      
    case 'default action':       // if no nodes are included in message
      drupal_set_message(t('You have not selected any items to send'), 'error');
      echo theme('page', '');
      return;
      
    case 'node':                 // callback that modifies appearance of each rendered node
      return;
      
    case 'body':                 // callback that modifies appearance of rendered body
      return;
      
    case 'querystring':          // callback that will return name=>value array for return links
      return;
      
    case 'deliver':              // callback to send the message
      return '_send_deliver';
      
    case 'confirm':              // callback action when complete
      return '_send_confirm';

    case 'recipient type':       // node or user 
      return 'user';
  }
  return;
}

function send_modules() {
  static $modules = array();
  if (!$modules) {
    foreach (module_implements('send') as $m) {
      $modules[$m] = module_invoke($m, 'send', 'name', $m);
    }
  }
  return $modules;
}

function _send($func) {
  require_once dirname(__FILE__) .'/send.inc';
  if (function_exists($func = '_send_'. $func)) {
    $args = func_get_args();
    unset($args[0]);
    return call_user_func_array($func, $args);
  }
}

I do not know what I have to do with this...

Could you tell me ?

Thank you