[penagwin]

From my understanding it depends on how naughty your current exit node has been. Most tor exits in my experience allow creation and you just need to verify another email (just use a random burner- they only block a few. Supposedly some well behaved exits require just a captcha but I've never seen it.

[ksaj]

It would be nice if they had a tor presence so there would be no need to traverse an exit node. A lot of other privacy-forward sites do exactly this.

[testvox]

They do https://protonmail.com/tor

[dfdub10]

They do with the premium tier.