CID in HTML emails vs. Gmail & Yandex.Mail?

Question

gmail

I would like to layout the letter in such a way that the user would see the pictures in Gmail without pressing the "show pictures" button.
There is a method of attaching a picture to a letter (inline) and calling it via CID
For example:

<td valign="top" bgcolor="#19305a" background="cid:header.jpg" style="height:175px;width:800px;">

image inserted into email
--mimepart_4e82be8259d8b_d3c..fdbc018da5aa
Content-Type: image/jpg; charset = utf-8
, the Content-Transfer-the Encoding: Base64-
the Content-Disposition header: inline
the Content-Id: <header.jpg>
/ 9j / 4AAQSkZJRgABAgAAZABkAAD / 7AARRHVja3kAAQAEAAAAPAAA / + 4ADkFk
b2JlAGTAAAAAAf / bAIQABgQEBAUEBgUFBgkGBQYJCwgGBggLDAoKCwoKDBAM
DAwMDAwQDA4PEA8ODBMTFBQTExwbGxscHx8fHx8fHx8fHwEHBwcNDA0YEBAY
But I see that Gmail still cuts out background. And Yandex.Mail does not display a picture.
1) Perhaps I have an error in the formation of headers. Someone can help?
2) Does it make sense to mess with it? Maybe Yandex and Gmail still won't show the picture embedded in the email?
I would be very grateful to those who give advice.
Thank you!

Answer 1

In any case, the background will be cut. I mentioned this more than once in my topics. Often the background can be implemented through the img tag, but not in all variations. Therefore, it is necessary to form design layouts in such a way as to do without backgrounds.