我找不到一个能真正满足最初问题的答案。

Mandrill是不可取的，因为它是新的定价政策，加上它需要一个后端服务，如果你想保持你的凭证安全。 最好隐藏你的电子邮件，这样你就不会出现在任何列表中(mailto解决方案暴露了这个问题，对大多数用户来说不方便)。 仅仅为了发送一封电子邮件而设置sendMail或需要一个后端是很麻烦的。

我提供了一个简单的免费服务，允许您发出标准的HTTP POST请求来发送电子邮件。它叫做PostMail，你可以使用JavaScript或jQuery简单地发布一个表单。当你注册时，它为你提供代码，你可以复制和粘贴到你的网站。下面是一些例子:

JavaScript:

<form id="javascript_form">
    <input type="text" name="subject" placeholder="Subject" />
    <textarea name="text" placeholder="Message"></textarea>
    <input type="submit" id="js_send" value="Send" />
</form>

<script>

    //update this with your js_form selector
    var form_id_js = "javascript_form";

    var data_js = {
        "access_token": "{your access token}" // sent after you sign up
    };

    function js_onSuccess() {
        // remove this to avoid redirect
        window.location = window.location.pathname + "?message=Email+Successfully+Sent%21&isError=0";
    }

    function js_onError(error) {
        // remove this to avoid redirect
        window.location = window.location.pathname + "?message=Email+could+not+be+sent.&isError=1";
    }

    var sendButton = document.getElementById("js_send");

    function js_send() {
        sendButton.value='Sending…';
        sendButton.disabled=true;
        var request = new XMLHttpRequest();
        request.onreadystatechange = function() {
            if (request.readyState == 4 && request.status == 200) {
                js_onSuccess();
            } else
            if(request.readyState == 4) {
                js_onError(request.response);
            }
        };

        var subject = document.querySelector("#" + form_id_js + " [name='subject']").value;
        var message = document.querySelector("#" + form_id_js + " [name='text']").value;
        data_js['subject'] = subject;
        data_js['text'] = message;
        var params = toParams(data_js);

        request.open("POST", "https://postmail.invotes.com/send", true);
        request.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

        request.send(params);

        return false;
    }

    sendButton.onclick = js_send;

    function toParams(data_js) {
        var form_data = [];
        for ( var key in data_js ) {
            form_data.push(encodeURIComponent(key) + "=" + encodeURIComponent(data_js[key]));
        }

        return form_data.join("&");
    }

    var js_form = document.getElementById(form_id_js);
    js_form.addEventListener("submit", function (e) {
        e.preventDefault();
    });
</script>

jQuery:

<form id="jquery_form">
    <input type="text" name="subject" placeholder="Subject" />
    <textarea name="text" placeholder="Message" ></textarea>
    <input type="submit" name="send" value="Send" />
</form>

<script>

    //update this with your $form selector
    var form_id = "jquery_form";

    var data = {
        "access_token": "{your access token}" // sent after you sign up
    };

    function onSuccess() {
        // remove this to avoid redirect
        window.location = window.location.pathname + "?message=Email+Successfully+Sent%21&isError=0";
    }

    function onError(error) {
        // remove this to avoid redirect
        window.location = window.location.pathname + "?message=Email+could+not+be+sent.&isError=1";
    }

    var sendButton = $("#" + form_id + " [name='send']");

    function send() {
        sendButton.val('Sending…');
        sendButton.prop('disabled',true);

        var subject = $("#" + form_id + " [name='subject']").val();
        var message = $("#" + form_id + " [name='text']").val();
        data['subject'] = subject;
        data['text'] = message;

        $.post('https://postmail.invotes.com/send',
            data,
            onSuccess
        ).fail(onError);

        return false;
    }

    sendButton.on('click', send);

    var $form = $("#" + form_id);
    $form.submit(function( event ) {
        event.preventDefault();
    });
</script>

再次坦白地说，我创建这个服务是因为我找不到合适的答案。

你可以在这篇文章中找到在JavaScript函数中放入的内容。

function getAjax() {
    try {
        if (window.XMLHttpRequest) {
            return new XMLHttpRequest();
        } else if (window.ActiveXObject) {
            try {
                return new ActiveXObject('Msxml2.XMLHTTP');
            } catch (try_again) {
                return new ActiveXObject('Microsoft.XMLHTTP');
            }
        }
    } catch (fail) {
        return null;
    }
}

function sendMail(to, subject) {
     var rq = getAjax();

     if (rq) {
         // Success; attempt to use an Ajax request to a PHP script to send the e-mail
         try {
             rq.open('GET', 'sendmail.php?to=' + encodeURIComponent(to) + '&subject=' + encodeURIComponent(subject) + '&d=' + new Date().getTime().toString(), true);

             rq.onreadystatechange = function () {
                 if (this.readyState === 4) {
                     if (this.status >= 400) {
                         // The request failed; fall back to e-mail client
                         window.open('mailto:' + to + '?subject=' + encodeURIComponent(subject));
                     }
                 }
             };

             rq.send(null);
         } catch (fail) {
             // Failed to open the request; fall back to e-mail client
             window.open('mailto:' + to + '?subject=' + encodeURIComponent(subject));
         }
     } else {
         // Failed to create the request; fall back to e-mail client
         window.open('mailto:' + to + '?subject=' + encodeURIComponent(subject));
     }
}

提供您自己的PHP(或任何语言)脚本来发送电子邮件。

window.open (mailto: test@example.com);如上所述 不采取任何措施来隐藏“test@example.com”电子邮件地址，以免被垃圾邮件机器人收集。我以前经常遇到这个问题。

var recipient="test";
var at = String.fromCharCode(64);
var dotcom="example.com";
var mail="mailto:";
window.open(mail+recipient+at+dotcom);

似乎有一个新的解决办法即将出现。它叫EmailJS。他们声称不需要服务器代码。你可以申请邀请。

2016年8月更新:EmailJS似乎已经上线了。你每月可以免费发送200封电子邮件，如果数量更多，还可以订阅。

在sendMail()函数中，将ajax调用添加到后端，您可以在服务器端实现此功能。

使用JavaScript或jQuery发送邮件

var ConvertedFileStream;
var g_recipient;
var g_subject;
var g_body;
var g_attachmentname;


function SendMailItem(p_recipient, p_subject, p_body, p_file, p_attachmentname, progressSymbol) {

    // Email address of the recipient 
    g_recipient = p_recipient;

   // Subject line of an email
    g_subject = p_subject;

   // Body description of an email
    g_body = p_body;

    // attachments of an email
    g_attachmentname = p_attachmentname;

    SendC360Email(g_recipient, g_subject, g_body, g_attachmentname);

}

function SendC360Email(g_recipient, g_subject, g_body, g_attachmentname) {
    var flag = confirm('Would you like continue with email');
    if (flag == true) {

        try {
            //p_file = g_attachmentname;
            //var FileExtension = p_file.substring(p_file.lastIndexOf(".") + 1);
           // FileExtension = FileExtension.toUpperCase();
            //alert(FileExtension);
            SendMailHere = true;

            //if (FileExtension != "PDF") {

            //    if (confirm('Convert to PDF?')) {
            //        SendMailHere = false;                    
            //    }

            //}
            if (SendMailHere) {
                var objO = new ActiveXObject('Outlook.Application');

                var objNS = objO.GetNameSpace('MAPI');

                var mItm = objO.CreateItem(0);

                if (g_recipient.length > 0) {
                    mItm.To = g_recipient;
                }

                mItm.Subject = g_subject;

                // if there is only one attachment                 
                // p_file = g_attachmentname;
                // mAts.add(p_file, 1, g_body.length + 1, g_attachmentname);

                // If there are multiple attachment files
                //Split the  files names
                var arrFileName = g_attachmentname.split(";");
                 // alert(g_attachmentname);
                //alert(arrFileName.length);
                var mAts = mItm.Attachments;

                for (var i = 0; i < arrFileName.length; i++)
                {
                    //alert(arrFileName[i]);
                    p_file = arrFileName[i];
                    if (p_file.length > 0)
                    {                     
                        //mAts.add(p_file, 1, g_body.length + 1, g_attachmentname);
                        mAts.add(p_file, i, g_body.length + 1, p_file);

                    }
                }

                mItm.Display();

                mItm.Body = g_body;

                mItm.GetInspector.WindowState = 2;

            }
            //hideProgressDiv();

        } catch (e) {
            //debugger;
            //hideProgressDiv();
            alert('Unable to send email.  Please check the following: \n' +
                    '1. Microsoft Outlook is installed.\n' +
                    '2. In IE the SharePoint Site is trusted.\n' +
                    '3. In IE the setting for Initialize and Script ActiveX controls not marked as safe is Enabled in the Trusted zone.');
        }
    }
  }