Configuring caching policies involves setting up HTTP headers like Cache-Control and Expires in your email's HTML code. These headers instruct the email client on how to cache the email content.
Cache-Control Header The Cache-Control header defines the caching mechanism. For example:
Cache-Control: max-age=3600, must-revalidate
This header sets the content to be cached for 3600 seconds (1 hour) and requires the client to revalidate the content after this period.
Expires Header The Expires header specifies a date and time after which the content is considered stale:
Expires: Wed, 21 Oct 2023 07:28:00 GMT
This header sets a specific expiration date for the cached content.