If you want to, you can use a Jetpack feature called Post by Email to send your WordPress posts via your favorite email client. There’s wide support for setting the title, tags, categories, as well as adding attachments and using shortcodes. But if you do…
the post arrives as a Classic Block
Source: Yes! Post by email lives (and finding hidden Jetpack modules) – CogDogBlog
Much as I enjoy using Jetpack with WordPress, I dislike that they’ve embraced the Gutenberg blocks editor completely, but not adapted to it. If you send a post to it via email or from other apps on iOS or through the Save as Draft feature, it’ll invariably get saved as a Classic Block and then must be edited to convert to individual blocks. This is not so problematic, as the end user sees a somewhat consistent output. But it sure is irritating UX.
I would love it if Jetpack could work on making this consistent and going all in on Gutenberg.