Gmail used to be good alright, but then it started to ask for my phone number all the time. I've switched to Tutanota recently, much better IMO, particularly the new client: https://mail.tutanota.com/
Same problem with the old GMX. "was that john.doe@gmx.de or john.doe@gmx.net" - I get it, people should be able to differentiate, but they're really not.
I'm using my own domain anyway. When your last name is your domain, it gets impossible to impersonate you with any free service. And as it's only 1 Euro, it's also cheap and easy.
I would use tutanota if they could change a simpler domain.
When I wake up on the second morning after I've registered an email account, it was impossible for me to remember whether the domain was tunanota, notatuna, nonanuta or tutanote...
I just tested tutanota. The interface is clean and nice but the encryption to external contacts is the same as in Gmail (link back to tutanota and shared passwords).
Avoiding links is the ultimate goal, hopefully Tutanota will integrate your suggestion or something similar. I've moved my entire family to Tutanota, which also works quite well. But you'll never convince everybody...
As far as I know self-destruct emails in Gmail are not end-to-end encrypted.
So I register bob@tutanota.com but forget to register bob@tutanota.de and anybody can squat it and impersonate me from the same service?
Not to mention they blocked my IP after registering 3 of the 5 available domains.