电子邮件回应示例

以下是一些有效和无效的电子邮件回应消息示例。

有效期：multipart/alternative

电子邮件回应通常包含三个部分：

• text/plain：消息的纯文本版本。
• text/vnd.google.email-reaction+json：回应部分。
• text/html：消息的 HTML 版本。

示例如下：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: multipart/alternative;
        boundary="----=_Part_0_2012232625.1697791227635"

------=_Part_0_2012232625.1697791227635
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Text body content
------=_Part_0_2012232625.1697791227635
Content-Type: text/vnd.google.email-reaction+json; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=99=83","version":1}
------=_Part_0_2012232625.1697791227635
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

<h1>HTML body content</h1>
------=_Part_0_2012232625.1697791227635--

单个有效的身体部位

电子邮件回应也可以仅包含一个正文部分，例如：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=99=83","version":1}

请注意，Content-Transfer-Encoding 可以是任何标准编码：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json
Content-Transfer-Encoding: base64

ewogICJlbW9qaSI6ICLwn46JIiwKICAidmVyc2lvbiI6IDEKfQ==

对于二进制编码（如 base64），JSON 必须采用 UTF-8 编码。

multipart/related 中有效的嵌套 multipart/alternative

如果回应是对包含内嵌附件的邮件，则可以生成包含包含附件的 multipart/related 正文部分和 multipart/alternative 部分的消息，如前面的示例所示。

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: multipart/related;
        boundary="----=_Part_0_2012232625.1697793303618"

------=_Part_0_2012232625.1697793303618
Content-Type: multipart/alternative;
        boundary="----=_Part_1_984213526.1697793303621"

------=_Part_1_984213526.1697793303621
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Text body content
------=_Part_1_984213526.1697793303621
Content-Type: text/vnd.google.email-reaction+json
Content-Transfer-Encoding: base64

ewogICJlbW9qaSI6ICLwn46JIiwKICAidmVyc2lvbiI6IDEKfQ==
------=_Part_1_984213526.1697793303621
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

<h1>HTML body content</h1>
------=_Part_1_984213526.1697793303621--

------=_Part_0_2012232625.1697793303618
Content-Type: image/png
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="1x1.png"

iVBORw0KGgoAAAANSUhEUgAAAAEAAAABAQMAAAAl21bKAAAAA1BMVEUAAACnej3aAAAAAXRSTlMA
QObYZgAAAApJREFUCNdjYAAAAAIAAeIhvDMAAAAASUVORK5CYII=
------=_Part_0_2012232625.1697793303618--

（请注意，multipart/related 正文部分应包含 RFC2387 中指定的其他字段，但这些字段与确定电子邮件回应是否有效无关。）

“JSON”格式无效

以下回应无效，因为 JSON 缺少闭合大括号：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=99=83","version":1

以下回应无效，因为 JSON 中包含尾随英文逗号：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=99=83","version":1,}

version 字段无效

以下回应无效，因为它缺少 version 字段：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=99=83"}

以下回应无效，因为 version 字段不是 1：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=99=83","version":2}

emoji 字段无效

以下回应无效，因为 emoji 字段为空：

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"","version":1}

以下回应无效，因为 emoji 字段不包含有效的表情符号。

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"A","version":1}

以下回应无效，因为两个零宽度连接符 (ZWJ) 字符之间缺少 ❤ 表情符号。请注意，第一个内容行的末尾的“=”字符表示 Quoted-Printable 编码中的软换行符。

From: [e-mail]
Message-ID: <[e-mail]>
Subject: subject
MIME-Version: 1.0
In-Reply-To: <[e-mail]>
Content-Type: text/vnd.google.email-reaction+json; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

{"emoji":"=F0=9F=91=A9=F0=9F=8F=BC=E2=80=8D=E2=80=8D=F0=9F=91=A8=F0=9F=8F=BE",=
"version":1}