https://smtpjs.com/
这个网站提供了代码如下。在autoJS里面可以运行,但是。。。。。找不到XMLHttpRequest😂

/* SmtpJS.com - v2.0.1 */
Email = {
    send: function(e, o, t, n, a, s, r, c) {
        var d = Math.floor(1e6 * Math.random() + 1),
            i = "From=" + e;
        i += "&to=" + o, i += "&Subject=" + encodeURIComponent(t), i += "&Body=" + encodeURIComponent(n), void 0 == a.token ? (i += "&Host=" + a, i += "&Username=" + s, i += "&Password=" + r, i += "&Action=Send") : (i += "&SecureToken=" + a.token, i += "&Action=SendFromStored", c = a.callback), i += "&cachebuster=" + d, Email.ajaxPost("https://smtpjs.com/v2/smtp.aspx?", i, c)
    },
    sendWithAttachment: function(e, o, t, n, a, s, r, c, d) {
        var i = Math.floor(1e6 * Math.random() + 1),
            m = "From=" + e;
        m += "&to=" + o, m += "&Subject=" + encodeURIComponent(t), m += "&Body=" + encodeURIComponent(n), m += "&Attachment=" + encodeURIComponent(c), void 0 == a.token ? (m += "&Host=" + a, m += "&Username=" + s, m += "&Password=" + r, m += "&Action=Send") : (m += "&SecureToken=" + a.token, m += "&Action=SendFromStored"), m += "&cachebuster=" + i, Email.ajaxPost("https://smtpjs.com/v2/smtp.aspx?", m, d)
    },
    ajaxPost: function(e, o, t) {
        var n = Email.createCORSRequest("POST", e);
        n.setRequestHeader("Content-type", "application/x-www-form-urlencoded"), n.onload = function() {
            var e = n.responseText;
            void 0 != t && t(e)
        }, n.send(o)
    },
    ajax: function(e, o) {
        var t = Email.createCORSRequest("GET", e);
        t.onload = function() {
            var e = t.responseText;
            void 0 != o && o(e)
        }, t.send()
    },
    createCORSRequest: function(e, o) {
        var t = new XMLHttpRequest;
        return "withCredentials" in t ? t.open(e, o, !0) : "undefined" != typeof XDomainRequest ? (t = new XDomainRequest).open(e, o) : t = null, t
    }
};


Email.send("from@you.com",
"to@them.com",
"This is a subject",
"this is the body",
"smtp.yourisp.com",
"username",
"password");