node连接exchange服务器发邮件

最近有需求，实现每天查询数据库获取数据后自动发邮件，在网上找node发邮件的资料，大多数是使用nodemailer，然而公司内部不能访问外网，也即不能通过QQ、网易邮箱这类的发邮件，要想对外发邮件，只能使用公司邮箱。公司邮箱服务器为exchange，Google找了下，发现node-ews、ews-javascript-api都可以实现这个功能，前者貌似不怎么更新了，因此最终选择了后者。

实现代码：

const ews = require('ews-javascript-api');
const ewsAuth = require('ews-javascript-api-auth');
const { logger } = require('../log/log');

const credential = {
	username: 'username',
	password: 'password'
}

ews.ConfigurationApi.ConfigureXHR(new ewsAuth.ntlmAuthXhrApi(credential.username, credential.password));
const exch = new ews.ExchangeService(ews.ExchangeVersion.Exchange2010);
exch.Credentials = new ews.WebCredentials(credential.username, credential.password);
exch.Url = new ews.Uri('https://host/Ews/Exchange.asmx')
// ews.EwsLogging.DebugLogEnabled = true;

/*
    subject: 邮件主题
    mailAddress: 收件人地址
    fileName: 发送附件的名称
    data: 附件内容，base64格式
*/
exports.sendEwsMail = (subject, mailAddress, fileName, data) => {
	const msgattach = new ews.EmailMessage(exch);
	msgattach.Subject = subject;
	msgattach.Body = new ews.MessageBody('DO NOT REPLY! This is Automatic E-Mail Sent');
	msgattach.ToRecipients.Add(mailAddress);
	msgattach.Attachments.AddFileAttachment(fileName, data);

	msgattach.SendAndSaveCopy().then((res) => {
		logger.info(res)
	}, (err) => {
		logger.info(err.stack)
	})
}

一开始未引入ews-javascript-api-auth这个库，执行代码报错401 UnAuthorized，身份验证不通过，引入该库，并加上下面这句代码解决。

ews.ConfigurationApi.ConfigureXHR(new ewsAuth.ntlmAuthXhrApi(credential.username, credential.password));