JSFiddle - React, Tailwind, and code Playground

HTML

<script src="//ajax.googleapis.com/ajax/libs/jqueryui/1.8/jquery-ui.min.js"></script>
<link rel="stylesheet" href="//ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/smoothness/jquery-ui.css">
<input type="text" name="email" class="emailAutocomplete" size="60" />

JavaScript

$(function() {
    var emaildomains = ['chollian.net',
        'daum.net',
        'empal.com',
        'facebook.com',
        'freechal.com',
        'gmail.com',
        'hanmir.com',
        'hotmail.com',
        'korea.com',
        'lycos.co.kr',
        'nate.com',
        'naver.com',
        'netian.com',
        'paran.com',
        'unitel.co.kr',
        'yahoo.co.kr'];

    $('input.emailAutocomplete').autocomplete({
        minLength: 0,
        source: function(request, response) {
            var mail_regex = /^([a-z\d_\+\.]+)@([a-z\d\-\.]*)$/;
            var match = mail_regex.exec(request.term);
            if(!match) return false;
            var matcher = new RegExp('^' + match[2], 'i');
            response(
                $.grep(emaildomains, function(item) {
                    return matcher.test(item);
                })
            );
        },
        focus:function() {
            return false;
        },
        select: function(event, ui) {
            this.value = this.value.replace(/@.*$/, '@') + ui.item.value;
            return false;
        }
    });
});