Why are the images being blocked from Gmail?
From my research, my images are being stored via HTTP and not HTTPS. How can we switch that in Marketo? Is this the problem.
You can implement SSL on your instance. There's a process and fee. Check with your account manager.
But w/o more info, there's no way for us to know why those images are "blocked". Did you try Display Images?
Our emails originally displayed images that were stored on Marketo's servers. This wasn't an issue until just recently (Marketo's DNS issue).
Why I'm concerned: I cloned a past email, that showed an image previously, sent an sample, and the image didn't populate. These emails are simple text emails, written with the new version of the Marketo's email client. They have one banner, stored in Marketo's 'images and files' section in Design Studio. You would think they would be stored in a secure location.
Note: We want to bypass the 'Display Images' prompt Gmail gives when opening an email that has src's with insecure protocols (HTTP). I'm not entirely sure that updating to a secure server will resolve the issue, just inferring after doing some research.
You wouldn't think they'd be in a secure version of your LP domain if that secure site doesn't exist!
You can serve them from under your pod (https://app-xxnn.marketo.com) if you want them to be natively secure (I say "natively" since some webmail clients pass images through a secure proxy anyway).