如何为 Amazon SES sendRawEmail 创建消息正文

Question

我尝试在使用 AWS Node.js SDK 时自定义标头。

sendEmail API 端点和随附的 SDK 方法似乎不支持自定义标头。

因此，合适的方法是sendRawEmail。

不幸的是，我找不到真正有助于撰写原始电子邮件的良好信息或软件包。这意味着发送纯文本和 html 格式并根据 RFC 2822 和 RFC 5322 创建消息正文和标头。

用 JavaScript 编写的组成原始主体的简单方法会是什么样子？

Answer 1

这是我想出的一个准系统函数，它只有作为AWS Javascript SDK依赖项。我一开始做错的一件事是 Base 64 编码RawMessage.Data，但AWS SDK已经解决了这个问题。

空行\n也很重要。

const sendRawEmail = async () => {

    // Set up from_name, from_email, to, subject, message_id, plain_text, html and configuration_set variables from database or manually

    var date = new Date();

    var boundary = `----=_Part${ Math.random().toString().substr( 2 ) }`;

    var rawMessage = [
        `From: "${ from_name }" <${ from_email }>`, // Can be just the email as well without <>
        `To: ${ to }`,
        `Subject: ${ subject }`,
        `MIME-Version: 1.0`,
        `Message-ID: <${ message_id }@eu-west-1.amazonses.com>`, // Will be replaced by SES
        `Date: ${ formatDate( date ) }`, // Will be replaced by SES
        `Return-Path: <${ message_id }@eu-west-1.amazonses.com>`, // Will be replaced by SES
        `Content-Type: multipart/alternative; boundary="${ boundary }"`, // For sending both plaintext & html content
        // ... you can add more headers here as decribed in https://docs.aws.amazon.com/ses/latest/DeveloperGuide/header-fields.html
        `\n`,
        `--${ boundary }`,
        `Content-Type: text/plain; charset=UTF-8`,
        `Content-Transfer-Encoding: 7bit`,
        `\n`,
        plain_text,
        `--${ boundary }`,
        `Content-Type: text/html; charset=UTF-8`,
        `Content-Transfer-Encoding: 7bit`,
        `\n`,
        html,
        `\n`,
        `--${ boundary }--`
    ]

    // Send the actual email
    await ses.sendRawEmail( {
        Destinations: [
            to
        ],
        RawMessage: {
            Data: rawMessage.join( '\n' )
        },
        Source: from_email, // Must be verified within AWS SES
        ConfigurationSetName: configuration_set, // optional AWS SES configuration set for open & click tracking
        Tags: [
            // ... optional email tags
        ]

    } ).promise();

}

这些是格式化日期标题的实用方法。您也可以简单地使用该moment库moment().format('ddd, DD MMM YYYY HH:MM:SS ZZ');，但这并不重要，因为日期标头无论如何都会被 AWS SES 覆盖。

// Outputs timezone offset in format ZZ
const getOffset = ( date ) => {

    var offset          = - date.getTimezoneOffset();
    var offsetHours     = Math.abs( Math.floor( offset / 60 ) );
    var offsetMinutes   = Math.abs( offset ) - offsetHours * 60;

    var offsetSign      = ( offset > 0 ) ? '+' : '-';

    return offsetSign + ( '0' + offsetHours ).slice( -2 ) + ( '0' + offsetMinutes ).slice( -2 );

}

// Outputs two digit inputs with leading zero
const leadingZero = ( input ) => ( '0' + input ).slice( -2 );

// Formats date in ddd, DD MMM YYYY HH:MM:SS ZZ
const formatDate = ( date ) => {

    var weekdays = [ 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun' ];

    var months = [ 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ];

    var weekday = weekdays[ date.getDay() ];

    var day = leadingZero( date.getDate() );

    var month = months[ date.getMonth() ];

    var year = date.getFullYear();

    var hour = leadingZero( date.getHours() );

    var minute = leadingZero( date.getMinutes() );

    var second = leadingZero( date.getSeconds() );

    var offset = getOffset( date );

    return `${ weekday }, ${ day } ${ month } ${ year } ${ hour }:${ minute }:${ second } ${ offset }`;

}