LightDrive Email reads your synchronized CardDAV contacts to provide names and addresses while you compose messages.
Create, edit, or delete a contact in the Vault Contacts app or a connected CardDAV client. After the change reaches LightDrive, use the contacts synchronization control in Email to refresh its read-only copy. Email will not overwrite the address book.
If a recipient does not appear, confirm that the contact has an email address and is stored in the LightDrive address book rather than a device-only or third-party account.