[OfficeJS] Outlook: store email in separate data store

Hi,

currently within an Outlook web addon via office-js it is not possible to store a mail in a separate data store (outside the users mailbox).
Via VSTO this is possible.

We would like to have this feature available via office-js as we are working on an encryption solution, and want to give the recipient of a mail the possibility to store unencrypted mails in a local data store, such that they are not synchronized with the mail server.

Regards,
Daniel