I remember back in time this service was amongst the highest praised of all providers. Seeing messages like this gives me a sad feeling that maybe indeed the ONLY way of being sure your email address won't vanish after X years, is sticking to the big providers (Hotmail/Outlook/Live, Yahoo, Gmail).
I know there is a lot of praise for services like Runbox, Fastmail, EUMX, Zoho, Yandex, ... too and it probably is unlikely any of those would disappear anytime soon. But few of us probably expected Bluebottle would disappear in the distant future ...
It would make one rather hesitant to consider an account outside of the big global players like Microsoft, Google or Yahoo...
(or a huge player inside a really big market ; mail.ru for example being not a global player but having such a popularity in a country with a huge market, that they're probably as likely to survive on the long haul as Yahoo, Hotmail or Gmail)