There is 3 ways to embed image in email:
1) Remote images (src="https://example.com/myimage.jpg") - some email clients will block them by default and ask permission to load them, because this is a potential privacy violation.
2) Base64 encoded image (src="data:image/jpg;base64....") - base64 increases size of email when image is big, might not work in some cases.
3) Attached image (src="cid:myimage.jpg") - probably the most reliable way this days
Some mail clients refuse to display one or another.
It is unclear which one you are using and what does 'broken' actually means.
------------------------------
Andrey Kudinov
Project Manager
MobileTelesystems PJSC
Europe/Moscow
------------------------------