Using ShareFile for sending encrypted e-mails / attachments is only taking care of the transport being safe.
However if you send a message/link to the wrong person then he/she is still able to open the e-mail / attachment.
It would be usefull and more secure to use a 2FA for the receipient. E.g. a SMS message / Phonecall or manual transmission of a second factor that is needed before the received attachment / message can be opened.