outlook-quickactions-hotfix.js

// ==UserScript==
// @name       outlook quick actions hotfix
// @namespace  www.rossdoran.com
// @version    1.7
// @description  m$.gfy
// @match      https://outlook.office.com/mail/*
// @match      https://outlook.live.com/*
// @require http://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js
// @require https://gist.github.com/raw/2625891/waitForKeyElements.js
// @run-at document-start
// ==/UserScript==

var hideRibbon = false; // switch to true if you want to hide the ribbon, or false if you want the ribbon to be shown

var ribbonCSS = hideRibbon ? " .HIqgw.n0tDR, #RibbonRoot  { display: none !important; height:0px !important; }" : "";

// custom style

 $('head').append(`<style type="text/css">
                  .nloVY.pz2Jt .bx9dt { min-width: -2px !important; }` + ribbonCSS +
                  `</style>`);

waitForKeyElements (".WP8_u .UWVIR", moveQuickActions);

waitForKeyElements(".QpoLy", moveDeleteAction); // comment out this line to keep the delete quick action on the right

waitForKeyElements(".C2IG3.LPIso.oTkSL.iDEcr.wk4Sg", navigateToInbox); // i can't fathom why this is necessary, but this line makes the Inbox link return to your inbox, as it should

function navigateToInbox(elem)
{
    $(elem).click(function()
                  {
$("button[aria-label='Close']").click();
    }
        );
}

function moveDeleteAction(elem)
{
    var elem = $(elem);
    var parent = elem.closest(`.hDNlA.lHRXq.iZbPU.JCRRb.G1NES,
                              .hDNlA.lHRXq.IjQyD.JCRRb.G1NES,
                              .hDNlA.lHRXq.epBmH.IMyk_,
                              .zKDWD.YbB6r.IKvQi.IjQyD.JCRRb.cSOXK.G1NES,
                              .zKDWD.YbB6r.IKvQi.IjQyD.JCRRb.G1NES,
                              .zKDWD.YbB6r.IKvQi.iZbPU.JCRRb.G1NES,
                              .zKDWD.YbB6r.IKvQi.iZbPU.wZij3.G1NES,
                              .zKDWD.YbB6r.IKvQi.IjQyD.EhiOs.wZij3.G1NES,
                              .zKDWD.YbB6r.IKvQi.epBmH.EhiOs,
                              .zKDWD.IKvQi.IjQyD.JCRRb.G1NES,
                              .zKDWD.IKvQi.iZbPU.JCRRb._KLsp.G1NES,
                              .zKDWD.IKvQi.iZbPU.JCRRb.G1NES,
                              .zKDWD.IKvQi.gPZmZ.JCRRb.G1NES,
                              .zKDWD.IKvQi.epBmH,
                              .hDNlA.lHRXq.gPZmZ.JCRRb.G1NES
                              `); // different for pinned, flagged, returning to inbox after deleting, etc.
    if (parent.length > 0)
    {
    var newParent = parent.find(`
    .XG5Jd.y1E5h.zItCb,
    .XG5Jd.hQj7T,
    .OD8Ue.hQj7T,
    .xc0ZS.hQj7T
    `).children().first();
    if (newParent.length > 0)
    {
        elem.detach().appendTo(newParent);
    }
    }
}

function moveQuickActions(elem)
{
    var elem = $(elem);

    var parent = elem.closest(
        `.XG5Jd.hQj7T,
        .xc0ZS.hQj7T,
        .OD8Ue.hQj7T`); // parent element of left items
    if (parent.length > 0)
    {
    var newParent = parent.children().first(); // append to first child of left item parent
    if (newParent.length > 0)
    {
        elem.detach().appendTo(newParent);
    }
    }
}

Work but this happened:

As you can see, buttons aren't close to each other :/

Why there are spaces?

Sorry, was abroad on holiday. Updated to latest version, seems perfect once again. @Peppins32 - I had a space between pin and delete when first loading the page, which went away after waiting a little while. I think that might be unavoidable.