From looking at the source code, this does appear to be a Ghost embedding bug. The HTML/CSS for the post itself does not constrain its own size from what I can tell.
I’m an amateur CSS/HTML sleuth, but from where I saw the width being set, it appeared to be done in the new Mastodon card. I haven’t upgraded to 6 to check myself.
There’s not a dedicated mastodon or bluesky embed, so you’re using the generic embed, right? Because these embeds use javascript to retrieve content, but email clients don’t run javascript, they’re going to be missing content. (For the embeds that DO work, there’s custom code specifically to grab a preview image and send it in the email where the embed would be, linked back to the source site. (If you email a youtube embed and look closely at it, you’ll see that happening.)
What would need to happen for these other embed types is for there to be code that handles them in a similar way.
Meanwhile, a workaround is to create a screenshot of the content, paste it into the post, and then link the image back to the source. That works on both web and email.
Thanks for your reply. What I am doing is pasting in the link, eg from Mastodon or Bluesky. In the preview it automatically turns into the embed, and displays fine. On the website it displays too. I am not sure what is needed to get it working in the email, but I will note that with Buttondown (which I also use), there is no issue with email embeds. I am not a technical expert in email embeds, but if Buttondown can get it to work I am sure Ghost can too. It’s really not a great solution to use screenshots (for a start, accessibility, but also it’s just not technically elegant). I hope Ghost can fix this, as embeds in emails feels like it should be table stakes.
