Recently, inbox.eu start to offer for users two options - biometric login to mailbox - can use fingerprint or PIN of mobile phone, face - I didn't test
.
And I saw that sometime ago some asked about mailbox deletion - now is possilbe delete mailbox or domain email by GDPR (by European Union's personal data security regulation) - it mean, that all your data will be deleted at once and without any possibility to restore it. I think it is better, because it complement the service with privacy.
But global Inbox.eu account, that I use for admin part - still not allowed delete
) Maybe only via Support - I didn't try.