Sending and receiving PGP-encrypted emails works perfectly with the Zoho browser/web client but I can't find any way to encrypt/decrypt these messages within the Zoho iOS email app. When I attempt to open an email from a contact whom I've exchanged keys with, I receive the message "Enable PGP extension to decrypt this email". Similarly, I can't find  any option to send an encrypted email within the iOS app.

Surely this isn't a feature for the web client only? Why would Zoho provide this feature but not allow it to be used from a mobile device?

Can someone let me know if I'm missing something? How do I send/receive PGP-encrypted emails via the Zoho iOS email app?