The image at https://i.emojiall.com/social/pix/svg/mail-bulk.svg is returning a 526 status code (Invalid SSL certificate). This image is loaded by an external script from kit.com in the newsletter section. This needs to be investigated and fixed, or the newsletter solution should be replaced.
Notes
-- erroneously posted by GC in rubyevents/rubyevents#963 (comment)