I've found the Windows 10 Mail App to be user-friendly, but I don't like how it saves all emails and attachments to disk as this can be bad for security and privacy.
I'm looking for an email-client which supports multiple providors (e.g. Outlook, Gmail) but which doesn't save any email information to disk. The closest way I can think of is an electron style client with disk cache disabled, but I'm unaware of any such email clients.
Thanks.