As I recall, in 14 years, they never asked for a telephone number.
You are welcome to continue (they thank you for it!) but you have no archive of anything you sent or received to that date. But if you don’t use your account regularly, they will suddenly empty it with no warning to you. If you understand French, is a possibility. They say “temporarily” but I don’t know how many days/months/years that has gone on. But after registration they will give you a choice: you cannot use your box until you either validate your phone number or buy a subscription: not security, just robbery! You can still register easily on mail.ee with no phone number. inbox.lv has an impossible, ever-increasing set of CAPTCHAS that literally go on forever: no registration.
