I have images in my automated email notifications (for example, product images and my logo in order confirmation emails), but they don't appear by default when I send these test emails to the Gmail account linked to my Shopify account. This happens when I view the email on both desktop and mobile. I've already tried the following:
1. the directions to add Shopify's SPF record to my domain host
2. added alt tags to all images and double-checked that links to all images start with "https://" (as described in this forum post)
3. On my Gmail account that isn't displaying the images by default, I've double-checked that my settings say I can "Always display external images" and that "Dynamic email" is checked. On any automated email from my shop, I've even clicked the button to "Always display images from XXX@XXXX.com" and even then, the images don't load by default.
I've tried placing a test order with another Gmail account, and it works fine. But given that it doesn't work on my main Gmail account, I'm concerned that some of my customers are seeing broken images.
If you can't get this resolved, have a look at BucketLynx.com. You should be able to upload your images to BucketLynx, then include the links to the BucketLynx URL of your image in your email.
We have several plan levels that start at $10 a month for small users and go up to unlimited.