[protonmail]

Hi! Note that you can also search the email body, but for now only on the Proton Mail web and desktop apps. We're working to bring the functionality to our mobile apps, however, implementing content search on an end-to-end encrypted service has some unique challenges: https://proton.me/blog/engineering-message-content-search.

Regarding Proton Calendar, you should be able to accept calendar invites from external services.

Can you please contact us at https://proton.me/support/troubleshooting?product=mail so we can take a closer look at both your search and calendar issues? Thanks.