RAC

var waitTime = 7; // In seconds
var group = 3012054; // 0 for no group check, otherwise people in this group will not receive the message
function sendMsg(userId, username) {
    function send() {
        $.post('//www.roblox.com/messages/send',{
            subject: "Greetings, I am inviting you to join Royal Ascendancy Core",
            body: "Royal Ascendancy Core is looking for skilled fighters to join our hybrid clan and we believe that you have that skill that will help us prosper and grow strong. If you believe that you have the skill and determination to join the clan then we gladly invite you! https://web.roblox.com/My/Groups.aspx?gid=2680440 is the link, Hope to see you soon! For the disc_rd, DM Sanctumis#0073",
            recipientid: userId,
            cacheBuster: new Date().getTime()
        }).done(function(response) {
            if (response.success == true) {
                console.log('Sent message to ' + username + ' (' + userId + ')');
            } else {
                console.log('Error sending to ' + username + ': ' + response.shortMessage);
            }
        });
    }
    if (group > 0) {
        $.get('//www.roblox.com/Game/LuaWebService/HandleSocialRequest.ashx?method=IsInGroup&playerid=' + userId + '&groupid=' + group, function(response) {
            if(response.indexOf('true') == -1) {
                send();
            } else {
                console.log('Didn\'t send a message to ' + username + ' because he is already in group ' + group + '.');
            }
        });
    } else {
        send();
    }
}

function run() {
    var timeout = 0;
    var elements = document.evaluate('//div[contains(@id,\'ctl00_cphRoblox_rbxGroupRoleSetMembersPane_GroupMembersUpdatePanel\')]//div[contains(@class,\'GroupMember\')]//span[contains(@class,\'Name\')]/a',document,null,XPathResult.UNORDERED_NODE_ITERATOR_TYPE,null);
    var currentNode = elements.iterateNext();
    while (currentNode) {
        (function(time,id,name) {
            setTimeout(sendMsg,time,id,name);
        })(timeout,currentNode.href.match(/\d+/)[0],currentNode.textContent);
        timeout+=waitTime*1000;
        currentNode = elements.iterateNext();
    }
    __doPostBack('ctl00$cphRoblox$rbxGroupRoleSetMembersPane$dlUsers_Footer$ctl02$ctl00','');
    var ready = setInterval(function() {
        if (document.getElementById('__EVENTTARGET').value == '') {
            clearInterval(ready);
            setTimeout(run,timeout);
        }
    }, 10);
}
var ready = setInterval(function() {
    if (document.readyState === 'complete') {
        clearInterval(ready);
        run();
    }
}, 10);