Hi,
I went through this post, looks like you are trying to do the export task using the Enstella. Enstella is a 3rd Party application and we do not know how to answer this post.
We have a similar product with NetApp called Single MailBox Recovery (SMBR).
https://www.netapp.com/us/products/management-software/single-mailbox-recovery.aspx
Also we provide another solution for customers who use Exchange o365 it is called Cloud control which will let tyou take backup of few o365 applications.
https://www.netapp.com/us/products/cloud-storage/saas-backup.aspx
Feel free to respond back if you have any questions or concerns.