Protonmail is a walled garden of its own because it has no IMAP or POP (hasn't had it for more than two years since it was requested). So you're stuck with using the Protonmail apps on iOS or Android or using the web version. None of them are good choices to have one's own copy of all mails in an easily portable form. The only option Protonmail provides is to individually save or print emails. So there's no easy way to export your mails and switch to another provider.
If it's really a beta in the true sense of the word, it's not reliable enough to export one's mails. It would be better to wait till it's out of beta for those who need flexibility to move out.
Beta features are reserved for paying customers (and in this case you also have to apply to get the IMAP functionality). Free accounts don't get it until it becomes stable.
> The best way is to upgrade your account to a paid account and take advantage of the numerous extra features we provide with paid accounts. [0]
