I discovered this recently and set it up - it’s been working well so far!
I’ve gone back to Thunderbird for email, which has been nice - but I also get an increasing number of long form Substack type emails that are just a pain to read on computers. I do not like long form reading on computers, and these emails usually qualify.
Anyway, this service (EU10/yr) is some guy’s hobby project that takes emails forwarded to it, renders them as HTML somewhere Pocket can grab, and adds them to your Pocket feed (it only has “add” permissions requested, not read or delete).
I then set up a mail forwarding rule (in the gmail interface - I do still use Google-hosted email, and given how hard it was to move my parents to that, I’ve no desire to move it any time soon) to push anything from Substack over to the private email address here, and when I sync the articles on my Kobo, I have new things to read!
It’s quite slick if you really hate reading on computer monitors and have been trying to push more of your reading to Kobo/eink. 