Folder structure reconstruction

MailServer/Exceptions/NoMailsInQueueException.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace SMTPServer.Exceptions
+{
+    class NoMailsInQueueException : Exception
+    {
+        public NoMailsInQueueException() : base()
+        {
+
+        }
+
+        public NoMailsInQueueException(string message) : base(message)
+        {
+
+        }
+
+        public NoMailsInQueueException(string message, Exception inner) : base(message, inner)
+        {
+
+        }
+    }
+}

MailServer/Exceptions/NotFoundException.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace MailServer.Exceptions
+{
+    class NotFoundException : Exception
+    {
+        public Type Type { get; set; }
+
+        public NotFoundException(Type type) : base()
+        {
+            Type = type;
+        }
+
+        public NotFoundException(string message, Type type) : base(message)
+        {
+            Type = type;
+        }
+
+        public NotFoundException(string message, Exception inner, Type type) : base(message, inner)
+        {
+            Type = type;
+        }
+    }
+
+    public enum Type
+    {
+        DOMAIN,
+        ACCOUNT,
+        ALIAS,
+        MAIL,
+        FOLDER
+    }
+}

MailServer/Exceptions/PortUsedException.cs

@@ -0,0 +1,22 @@
+using System;
+
+namespace SMTPServer.Exceptions
+{
+    public class PortUsedException : Exception
+    {
+        public PortUsedException() : base()
+        {
+
+        }
+
+        public PortUsedException(string message) : base(message)
+        {
+
+        }
+
+        public PortUsedException(string message, Exception inner) : base(message, inner)
+        {
+            
+        }
+    }
+}