Convert Base64 HTML to email using cid

Question

We have a tool that gives us html with embedded images like:

data: images / PNG; base64,1234

We want all images to be extracted and changed to cid images.

Is there an easy way to extract all inline base64 images and convert them to attachments using cid: tags?

We use MailMessage for email and SmtpClient for sending email.

The problem with inline images in base64 is that not all email clients accept this method.