There are several methods to implement preloading of assets in email marketing:
Inline CSS: By embedding critical CSS directly within the HTML of the email, you can ensure that styles are applied immediately as the email loads. Base64 Encoding: This method allows you to embed small images directly into your email's HTML, reducing the number of HTTP requests and speeding up image loading times. Preload Links: Using the <link rel="preload"> tag, you can instruct the email client to load important assets such as fonts or large images in the background.