tamper.js

// ==UserScript==
// @name         Почта mail.ru
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       You
// @match        https://e.mail.ru/*
// @grant        none
// @require http://code.jquery.com/jquery-latest.js
// ==/UserScript==

(function() {
    'use strict';

    // http://www.appelsiini.net/projects/viewport
    (function($){$.belowthefold=function(element,settings){var fold=$(window).height()+$(window).scrollTop();return fold<=$(element).offset().top-settings.threshold;};$.abovethetop=function(element,settings){var top=$(window).scrollTop();return top>=$(element).offset().top+$(element).height()-settings.threshold;};$.rightofscreen=function(element,settings){var fold=$(window).width()+$(window).scrollLeft();return fold<=$(element).offset().left-settings.threshold;};$.leftofscreen=function(element,settings){var left=$(window).scrollLeft();return left>=$(element).offset().left+$(element).width()-settings.threshold;};$.inviewport=function(element,settings){return!$.rightofscreen(element,settings)&&!$.leftofscreen(element,settings)&&!$.belowthefold(element,settings)&&!$.abovethetop(element,settings);};$.extend($.expr[':'],{"below-the-fold":function(a,i,m){return $.belowthefold(a,{threshold:0});},"above-the-top":function(a,i,m){return $.abovethetop(a,{threshold:0});},"left-of-screen":function(a,i,m){return $.leftofscreen(a,{threshold:0});},"right-of-screen":function(a,i,m){return $.rightofscreen(a,{threshold:0});},"in-viewport":function(a,i,m){return $.inviewport(a,{threshold:0});}});})(jQuery);

    $.noConflict();
    jQuery(document).ready(function($) {
        $(document).keydown(function (e) {
            //alert(e.which);
            if (e.which == 68) { // d
                if ($('#b-thread:visible').length > 0) {
                    var more = $('[data-mnemo="letter"].b-letter_expanded [data-group="more"]:in-viewport:first');
                    more.find('.js-preload-click').click();
                    more.find('[data-name="remove"]').click();
                }
                else if ($('#b-letters:visible').length > 0) {
                    $('.b-toolbar .b-checkbox').click();
                    $('.b-toolbar [data-name=remove]').click();
                }
            }
        });
    });

    // Your code here...
})();