Encryption of emails to patients

Hi
I have been in contact with the ICO to discuss various issues surrounding GDPR. They emphasised the importance of encrypting emails sent to patients. As far as I know, Clinic Office doesn’t have this feature at the moment so could you clarify whether this will be introduced, and if not, is there a form of email encryption software (preferably free!) that can be used from within the Clinic Office software, so that we can comply with this request?
Many thanks, Lucy