MS Outlook 365 Add-In by SecurelyShare is an email security solution that integrates with Microsoft Outlook 365, including both the client application and Outlook Web Access. The add-in provides encryption capabilities for email body content and attachments through a single-click interface. The solution addresses file size limitations in MS Outlook by enabling the transmission of large attachments. It encrypts both emails and attachments before sending, supporting various file types including Microsoft Office documents, image files (JPEG, PNG), and PDF files. The add-in includes on-the-fly watermarking functionality to add watermarks to files as a deterrent against unauthorized usage. It features automatic privacy enablement that scans and redacts pattern-based sensitive data while files are in transit. Access controls on shared data can be regulated from a central server. The solution supports communication with both internal and external domain email addresses. Recipients can access encrypted emails with policies seamlessly regardless of their domain. The add-in operates within the existing Outlook interface without requiring changes to user workflows.