Standard email is not end-to-end encrypted. Attachments sit on servers in plain text.
Encrypted Sharing
Tresorit Send: E2E up to 5 GB. Password, expiration, download limit. OnionShare: Via Tor, no third party. Wormhole.app: Browser E2E, expires after download.
Cloud Storage
Google Drive, Dropbox, OneDrive. Provider can access. Set expirations, restrict access.
Archives
7-Zip AES-256. File one channel, password another.
Practices
Separate channels for file and password. Expirations. Delete after confirmation. Minimum permissions.
