Is it necessary to have a hardware device for this to function? I'd love to pay $99/year for a 120 GB encrypted email service, but don't want the hassle of owni

Is it necessary to have a hardware device for this to function? I'd love to pay $99/year for a 120 GB encrypted email service, but don't want the hassle of owning more stuff. I'd go with ProtonMail but it's seriously expensive for the data price (24€/mo = 288€/yr for just 20GB). I also can't imagine that having a hardware device in-home actually reduces the unit costs of that storage, so if this were an on-line service priced even cheaper, I'd love to pay for it. My concerns echo those of commenter 'andr'.