Cleaned & Hardened Email.cs

smtpproxy.net/Email.cs

@@ -1,29 +1,47 @@
+using System;
 using System.Collections.Generic;
 
-namespace smtpproxy.net;
-
-public class Email
+namespace smtpproxy.net
 {
-	public string FromIP;
-
-	public string sHELO;
-
-	public string sMAIL;
-
-	public string sDATA;
-
-	public List<string> sRCPTs;
-
-	public string GetRecipientEmail(string sRCPTTo)
+    public class Email
     {
-		return sRCPTTo.ToLower().Replace("rcpt to:", "").Replace("<", "")
-			.Replace(">", "")
-			.Replace("\r", "")
-			.Replace("\n", "");
-	}
+        public string FromIP { get; set; }
+        public string sHELO { get; set; }
+        public string sMAIL { get; set; }
+        public string sDATA { get; set; }
+        public List<string> sRCPTs { get; set; }
 
         public Email()
         {
+            FromIP = string.Empty;
+            sHELO = string.Empty;
+            sMAIL = string.Empty;
+            sDATA = string.Empty;
             sRCPTs = new List<string>();
         }
+
+        public string GetRecipientEmail(string sRCPTTo)
+        {
+            if (string.IsNullOrEmpty(sRCPTTo))
+                return string.Empty;
+
+            string cleaned = sRCPTTo
+                .Replace("\r", "")
+                .Replace("\n", "")
+                .Replace("<", "")
+                .Replace(">", "")
+                .Trim();
+
+            if (cleaned.StartsWith("rcpt to:", StringComparison.OrdinalIgnoreCase))
+            {
+                cleaned = cleaned.Substring(8).Trim();
+            }
+            else if (cleaned.StartsWith("rcpt to", StringComparison.OrdinalIgnoreCase))
+            {
+                cleaned = cleaned.Substring(7).Trim();
+            }
+
+            return cleaned.ToLowerInvariant();
+        }
+    }
 }