Customize menu tabs.php

<?php
/**
 * Implements hook_user_view_alter().
 */
function mymodule_user_view_alter(&$build) {
  // Insert the contact link into the body of the display page.
  if ($build['#account']->data['contact']) {
    $link_text = $build['#account']->field_first_name['und'][0]['safe_value'] ? "email " . $build['#account']->field_first_name['und'][0]['safe_value'] : "email";
    $contact_link = l($link_text,'user/' . $build['#account']->uid . '/contact');
    $build['contact_link'][0]['#markup'] = "<div class=\"field\"><div class=\"field-label\">" . t('Contact') . ":&nbsp;</div><div class=\"field-items\"><div class=\"field-item even\">" . $contact_link . "</div></div></div>";
    $build['#group_children']['contact_link'] = 'group_user_details';
  }
}

/**
 * Implements hook_menu_alter().
 */
function mymodule_menu_alter(&$items) {
  // Remove the 'contact' tab.
  $items['user/%user/contact']['type'] = MENU_CALLBACK;
}