Have you ever received an entire email that looks like this?
If I can't get the critical content of your message in my preview screen, I won't give it 15 seconds of attention. When you put everything in an image, you're just out of luck. My reader won't display images without without my permission and I only give that permission when I know and trust the source of every attachment.*
I get emails like this regularly (like multiples per day) from at least one national merchant. I also get 5-10 emails from media companies with subject lines like: "WEATHER UPDATE: we stayed under 100 degrees." Or from my doctors or insurance companies like: "Tips for boosting brain health." I also get transcribed voicemails of all the phone calls that I don't answer from spammers. (most of those are "I can't understand this" because they waited until the beep to "hang up on me.")
I can't block the senders because occasionally I want to get their email - like a receipt or confirmation.
My strategy is to just select everything from today, unselect the 2 or 3 real emails, and use a 1-click command to shuffle these off to another folder. The "IGNORE" folder collects 15-30 messages a day from 3-6 correspondents. Meanwhile my Inbox has a manageable 4-8 messages that I really want. Occasionally I have to go back to the IGNORE folder because I inadvertently grabbed one I needed. Periodically I trash everything but the last few days and start over.
Folks: save your marketing spam. I know where to find you when I need you.
* "Trust the source" means I may not look at the cute cat pictures from a technologically reliable friend and certainly not an ad from a dicey vendor. It may make me seem obsessive, but I send images and reading matter as attachments - with a note in text as to the file name and size so the recipient knows they're authentic. For recipients who don't know me (or mailing lists), I save the originals to an online sharing service such as Dropbox, MS OneDrive, or Google Drive, and send the link.