If you're in this boat, the easiest way to get a raw email is to use the "raw" link on lists.sr.ht, which is hidden away under the "details" button.
Source: https://man.sr.ht/git.sr.ht/send-email.md
This does not appear to be available, or I can't find it, very possible as well!
Yeah, this isn't implemented yet.
Basically I foresee this being underneath a
<details>+<summary>tag in the header of the email, which would also include things like the message ID.
This is implemented, being deployed now.