I have an HTML template with <img> tag to display a QR code representation of a user ID, for that I simply used DATA URL technique src="data:image/png;base64, base64String as suggested by https://sendgrid.com/blog/embedding-images-emails-facts/ under the section Inline Embedding (Base64 Encoding).
This is working in outlook, but there seems to be a problem for Gmail. What is the best way to display this QR code in email clients, especially in Gmail. Note that, I do not have an actual image file as the QR is generated from the user ID, at most I just have the byte array representing the QR image.
I am using sendgrid to send the emails.