Outlook 无法在我的 MIME 中读取 PNG

PNG can't be read in my MIME by Outlook

我在 MIME 消息中将 PNG 作为 Base64 字符串写入。但我无法从 Outlook 中读取它,甚至无法使用 Windows 默认图像查看器打开添加的图像。

虽然,如果我执行以下步骤,Windows 可以阅读它:

因此我想我误用了 MIME 格式:这是我的 MIME 格式:

Content-Type: multipart/mixed; boundary="--boundary_0_a91d264e-016c-4b31-9a7a-e8e154b805edPVE"
Content-Transfer-Encoding: binary
MIME-Version: 1.0
X-Mailer: MIME-tools 5.411 (Entity 5.404)

This is a multi-part message in MIME format ...
----boundary_0_a91d264e-016c-4b31-9a7a-e8e154b805edPVE
Content-Type: text/xml
Content-Disposition: form-data; name="body";filename="PDA_P400404_9393_20150601.190623_00008_INIT.XML" 
Content-Transfer-Encoding: base64 

PD94bWwgdmVyc2lvbj0iM...first block of base 64 XML data, perfectly read..g0K


----boundary_0_a91d264e-016c-4b31-9a7a-e8e154b805edPVE
Content-Type: image/png
Content-Disposition: form-data; name="body";filename="PDA_P400404_9393_20150601.190623_00008_SIGNAGENT.PNG" 
Content-Transfer-Encoding: base64 
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

----boundary_0_a91d264e-016c-4b31-9a7a-e8e154b805edPVE--

Content-Transfer-Encoding: base64 和内容的开头之间必须有一个分隔线 (/r/n)。

Content-Transfer-Encoding: base64 

iVBORw0KGgoAAAANSUhEUgAAAOYAAABuCAIAAAC86/