Sensitive PII Information Detection in Email Sends using Azure AI, .NET and Twilio SendGrid

dotnet new console -n SensitivePiiEmailApp
cd SensitivePiiEmailApp

dotnet add package Azure.AI.TextAnalytics
dotnet add package SendGrid

public static class AppConfig
{
    // Replace with your actual Azure Cognitive Services Key and Endpoint
    public const string AzureCognitiveServicesEndpoint = "https://<YOUR-TEXTANALYTICS-ENDPOINT>.cognitiveservices.azure.com/";
    public const string AzureCognitiveServicesKey = "<YOUR-TEXTANALYTICS-KEY>";
    // Replace with your actual SendGrid Key
    public const string SendGridApiKey = "<YOUR-SENDGRID-API-KEY>";
    // Sender email and name
    public const string SenderEmail = "sender@example.com";
    public const string SenderName = "Sender Demo";
}

using Azure;
using Azure.AI.TextAnalytics;
public class PiiDetector
{
    private readonly TextAnalyticsClient _client;
    public PiiDetector()
    {
        var credentials = new AzureKeyCredential(AppConfig.AzureCognitiveServicesKey);
        _client = new TextAnalyticsClient(new Uri(AppConfig.AzureCognitiveServicesEndpoint), credentials);
    }
    public (bool piiFound, string redactedText) DetectAndRedactPII(string text)
    {
        var options = new RecognizePiiEntitiesOptions
        {
            DomainFilter = PiiEntityDomain.ProtectedHealthInformation
        };
        // Recognize PII in the text
        var response = _client.RecognizePiiEntities(text, "en", options);
        // Return the redacted text (PII replaced with '*')
        // and a flag indicating whether PII was found or not
        var redactedText = response.Value.RedactedText;
        bool piiFound = response.Value.Count > 0;
        return (piiFound, redactedText);
    }
}

using SendGrid;
using SendGrid.Helpers.Mail;
public class EmailService
{
    private readonly SendGridClient _client;
    public EmailService()
    {
        _client = new SendGridClient(AppConfig.SendGridApiKey);
    }
    public async Task<bool> SendEmailAsync(string toEmail, string toName, string subject, string bodyContent)
    {
        var from = new EmailAddress(AppConfig.SenderEmail, AppConfig.SenderName);
        var to = new EmailAddress(toEmail, toName);
        var msg = new SendGridMessage
        {
            From = from,
            Subject = subject,
            PlainTextContent = bodyContent,
            HtmlContent = $"<p>{bodyContent}</p>"
        };
        msg.AddTo(to);
        // Optionally configure additional properties
        // For example: msg.SetClickTracking(false, false);
        var response = await _client.SendEmailAsync(msg).ConfigureAwait(false);
        // Return true if the message was successfully queued for delivery (2xx status)
        return response.IsSuccessStatusCode;
    }
}

// Initialize services
var piiDetector = new PiiDetector();
var emailService = new EmailService();
// Sample email content that might contain PII
Console.WriteLine("Enter the email body (sample: My SSN is 123-45-6789):");
string emailBody = Console.ReadLine();
// Detect PII
var (piiFound, redactedText) = piiDetector.DetectAndRedactPII(emailBody);
if (piiFound)
{
    Console.WriteLine("Sensitive PII detected in the email body.");
    // Decide what to do:
    // 1) Block sending
    // 2) Send masked version
    // For demonstration, let's choose to send the redacted text:
    Console.WriteLine("Sending redacted content...");
    // Replace the original email body with the redacted text
    emailBody = redactedText;
}
else
{
    Console.WriteLine("No PII detected, sending the original content...");
}
// Send the email
Console.Write("Enter recipient email: ");
string recipientEmail = Console.ReadLine();
Console.Write("Enter recipient name: ");
string recipientName = Console.ReadLine();
bool result = await emailService.SendEmailAsync(recipientEmail, recipientName, 
    "Sensitive PII Detection Demo", emailBody);
if (result)
{
    Console.WriteLine("Email sent successfully!");
}
else
{
    Console.WriteLine("Failed to send the email.");
}
Console.WriteLine("Press any key to exit...");
Console.ReadKey();

dotnet run