Advanced iframe debug console – l: local messages, r: remote messages

User agent: CCBot/2.0 (https://commoncrawl.org/faq/)

Headers of https://mailchi.mp/firstchurchboston/worship-4942459?e=%5BUNIQID%5D:
HTTP/1.1 200 OK
Server: openresty
Content-Type: text/html; charset=UTF-8
Vary: Accept-Encoding
Content-Location: https://us7.campaign-archive.com/?u=2f3234fc94ecc4df09a638f3f&id=b417144489&e=%5BUNIQID%5D
Vary: Accept-Encoding
X-UA-Compatible: IE=edge,chrome=1
X-Mc-Customer-Tier: free
Date: Sun, 28 May 2023 23:13:51 GMT
Content-Length: 0
Connection: keep-alive
Set-Cookie: _mcid=1.b1774e862ed56777127c41bc824978f9.bca2f10b4f8abd492d588ac61ad755c8467b98c44bfd63e5af07e7e608bd2cec; expires=Mon, 27-May-2024 23:13:51 GMT; Max-Age=31536000; path=/
Set-Cookie: _mc_anon_id=deleted; expires=Thu, 01-Jan-1970 00:00:01 GMT; Max-Age=0; path=/

The page does exist and no X-Frame-Options header was found. But there can still be a iframe blocker script on this page. Go here for a full check.