如何阻止电子邮件中的嵌入图像被 GMail 显示为附件？

Question

I am sending HTML emails with embedded images (as attachments) and the images display as expected in GMail.我正在发送带有嵌入图像（作为附件）的 HTML 电子邮件，并且图像在 GMail 中按预期显示。 However they also show up as attachments under the email.但是，它们也显示为电子邮件下的附件。 Does anyone know how to avoid this ie I want them in the email only and not listed as attachments.有谁知道如何避免这种情况，即我只希望它们出现在电子邮件中，而不是作为附件列出。 I have used "Content-Disposition: inline".我使用过“内容处理：内联”。 I am using Spring and JavaMail.我正在使用 Spring 和 JavaMail。

Here is what my mails end up like.这是我的邮件最终的样子。 Can anyone see whats wrong?任何人都可以看到有什么问题吗？

Delivered-To: ...
...
Subject: ...
MIME-Version: 1.0
Content-Type: multipart/mixed; 
    boundary="----=_Part_0_1248835444.1288246311187"

------=_Part_0_1248835444.1288246311187
Content-Type: multipart/related; 
    boundary="----=_Part_1_592250078.1288246311197"

------=_Part_1_592250078.1288246311197
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

<html>
<body>
<p><img src="cid:a0"/></p>
</body>
</html>
------=_Part_1_592250078.1288246311197
Content-Type: image/x-png
Content-Transfer-Encoding: base64
Content-Disposition: inline
Content-ID: <a0>

iVBORw0KGgoAAAANSUhEUgAAAPAAAABQCAYAAAAnSfh8AAAACXBIWXMAAC4jAAAuIwF4pT92AAAA
...
Qcz8hzyUxqGHjkNbsY4Df5iBg6OIwafQHBxFjP8PAIwl43uhncLdAAAAAElFTkSuQmCC
------=_Part_1_592250078.1288246311197--

------=_Part_0_1248835444.1288246311187--

Answer 1

It is possible to get such a mail body out of GMail by following these steps:可以按照以下步骤从 GMail 中获取此类邮件正文：

enable in Gmail Labs "Inserting images by Kent T"在 Gmail 实验室中启用“插入 Kent T 的图片”
write an mail and embed an image into the mail写一封邮件并将图像嵌入邮件中
send the mail to yourself给自己发邮件
open the mail.打开邮件。 On the upper right corner, press the picture with the arrow down (right near Reply) and press "Show original".在右上角，按向下箭头的图片（在回复附近），然后按“显示原件”。 There you will find an example of such a mail.在那里您将找到此类邮件的示例。

I did this and got following result, where the image is not listed as attachement.我这样做并得到以下结果，其中图像未列为附件。 Maybe this mail body helps you to create a proper mail with Spring and JavaMail:也许这个邮件正文可以帮助您使用 Spring 和 JavaMail 创建正确的邮件：

MIME-Version: 1.0
...
Subject: ...
From: ...
To: ...
Content-Type: multipart/related; boundary=000e0cd62fb69a9c280493a7a1c0

--000e0cd62fb69a9c280493a7a1c0
Content-Type: multipart/alternative; boundary=000e0cd62fb69a9c250493a7a1bf

--000e0cd62fb69a9c250493a7a1bf
Content-Type: text/plain; charset=ISO-8859-1

[image: abc.png]

--000e0cd62fb69a9c250493a7a1bf
Content-Type: text/html; charset=ISO-8859-1

<img src="cid:ii_12bf191c5eab934e" alt="abc.png" title="abc.png"><br>

--000e0cd62fb69a9c250493a7a1bf--
--000e0cd62fb69a9c280493a7a1c0
Content-Type: image/png; name="abc.png"
Content-Transfer-Encoding: base64
Content-ID: <ii_12bf191c5eab934e>
X-Attachment-Id: ii_12bf191c5eab934e

iVBORw0KGgoAAAANSUhEUgAAAJ4AAADLCAIAAAAQpL1oAAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA
...

Answer 2

Using Spring you can do that like this:使用 Spring 你可以这样做：

MimeMessagePreparator message = mimeMessage -> {
        MimeMessageHelper mimeMessageHelper = new MimeMessageHelper(mimeMessage, true, "UTF-8");
        mimeMessageHelper.setFrom(new InternetAddress(emailSender));
        mimeMessageHelper.setTo("user@server.com");
        mimeMessageHelper.setSubject("A subject");
        String html = ... // contains a tag <img src='cid:logoIcon'>
        mimeMessageHelper.setText(html, true);

        mimeMessageHelper.addInline("logoIcon", new ClassPathResource("/data/images/logo.png"));
    };
mailSender.send(message);

Answer 3

For Gmail, Be careful to have a content-id with only alphanumeric characters !对于 Gmail，请注意内容 ID 仅包含字母数字字符！

I had spaces in my CID and only GMAIL was not displaying correctly.我的 CID 中有空格，只有 GMAIL 显示不正确。 I removed spaces and everything went right.我删除了空格，一切顺利。

** I strongly suggest to use a hash function like md5 to name the cid ** ** 我强烈建议使用像md5这样的哈希函数来命名 cid **

如何阻止电子邮件中的嵌入图像被 GMail 显示为附件？

问题描述

3 个解决方案

解决方案1
5 已采纳 2010-10-28 06:47:56

解决方案2
0 2020-11-03 11:05:31

解决方案3
0 2021-07-19 23:29:22

如何阻止电子邮件中的嵌入图像被 GMail 显示为附件？

问题描述

3 个解决方案

解决方案1 5 已采纳 2010-10-28 06:47:56

解决方案2 0 2020-11-03 11:05:31

解决方案3 0 2021-07-19 23:29:22

解决方案1
5 已采纳 2010-10-28 06:47:56

解决方案2
0 2020-11-03 11:05:31

解决方案3
0 2021-07-19 23:29:22