src/log4net/Appender/SmtpAppender.cs - logging-log4net - Git at Google

 #region Apache License
 //
 // Licensed to the Apache Software Foundation (ASF) under one or more
 // contributor license agreements. See the NOTICE file distributed with
 // this work for additional information regarding copyright ownership.
 // The ASF licenses this file to you under the Apache License, Version 2.0
 // (the "License"); you may not use this file except in compliance with
 // the License. You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
 #endregion

 using System;
 using System.IO;
 using System.Text;

 using System.Net.Mail;
 using log4net.Core;

 namespace log4net.Appender
 {
   /// <summary>
   /// Send an e-mail when a specific logging event occurs, typically on errors
   /// or fatal errors.
   /// </summary>
   /// <remarks>
   /// <para>
   /// The number of logging events delivered in this e-mail depend on
   /// the value of <see cref="BufferingAppenderSkeleton.BufferSize"/> option. The
   /// <see cref="SmtpAppender"/> keeps only the last
   /// <see cref="BufferingAppenderSkeleton.BufferSize"/> logging events in its
   /// cyclic buffer. This keeps memory requirements at a reasonable level while
   /// still delivering useful application context.
   /// </para>
   /// <note type="caution">
   /// Authentication and setting the server Port are only available on the MS .NET 1.1 runtime.
   /// For these features to be enabled you need to ensure that you are using a version of
   /// the log4net assembly that is built against the MS .NET 1.1 framework and that you are
   /// running the your application on the MS .NET 1.1 runtime. On all other platforms only sending
   /// unauthenticated messages to a server listening on port 25 (the default) is supported.
   /// </note>
   /// <para>
   /// Authentication is supported by setting the <see cref="Authentication"/> property to
   /// either <see cref="SmtpAuthentication.Basic"/> or <see cref="SmtpAuthentication.Ntlm"/>.
   /// If using <see cref="SmtpAuthentication.Basic"/> authentication then the <see cref="Username"/>
   /// and <see cref="Password"/> properties must also be set.
   /// </para>
   /// <para>
   /// To set the SMTP server port use the <see cref="Port"/> property. The default port is 25.
   /// </para>
   /// </remarks>
   /// <author>Nicko Cadell</author>
   /// <author>Gert Driesen</author>
   public class SmtpAppender : BufferingAppenderSkeleton
   {
     #region Public Instance Constructors

     /// <summary>
     /// Default constructor
     /// </summary>
     /// <remarks>
     /// <para>
     /// Default constructor
     /// </para>
     /// </remarks>
     public SmtpAppender()
     {
     }

     #endregion // Public Instance Constructors

     #region Public Instance Properties

     /// <summary>
     /// Gets or sets a comma- or semicolon-delimited list of recipient e-mail addresses (use semicolon on .NET 1.1 and comma for later versions).
     /// </summary>
     /// <value>
     /// <para>
     /// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
     /// </para>
     /// <para>
     /// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
     /// </para>
     /// </value>
     /// <remarks>
     /// <para>
     /// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
     /// </para>
     /// <para>
     /// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
     /// </para>
     /// </remarks>
     public string To
     {
       get { return m_to; }
       set { m_to = MaybeTrimSeparators(value); }
     }

     /// <summary>
     /// Gets or sets a comma- or semicolon-delimited list of recipient e-mail addresses
     /// that will be carbon copied (use semicolon on .NET 1.1 and comma for later versions).
     /// </summary>
     /// <value>
     /// <para>
     /// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
     /// </para>
     /// <para>
     /// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
     /// </para>
     /// </value>
     /// <remarks>
     /// <para>
     /// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
     /// </para>
     /// <para>
     /// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
     /// </para>
     /// </remarks>
     public string Cc
     {
       get { return m_cc; }
       set { m_cc = MaybeTrimSeparators(value); }
     }

     /// <summary>
     /// Gets or sets a semicolon-delimited list of recipient e-mail addresses
     /// that will be blind carbon copied.
     /// </summary>
     /// <value>
     /// A semicolon-delimited list of e-mail addresses.
     /// </value>
     /// <remarks>
     /// <para>
     /// A semicolon-delimited list of recipient e-mail addresses.
     /// </para>
     /// </remarks>
     public string Bcc
     {
       get { return m_bcc; }
       set { m_bcc = MaybeTrimSeparators(value); }
     }

     /// <summary>
     /// Gets or sets the e-mail address of the sender.
     /// </summary>
     /// <value>
     /// The e-mail address of the sender.
     /// </value>
     /// <remarks>
     /// <para>
     /// The e-mail address of the sender.
     /// </para>
     /// </remarks>
     public string From
     {
       get { return m_from; }
       set { m_from = value; }
     }

     /// <summary>
     /// Gets or sets the subject line of the e-mail message.
     /// </summary>
     /// <value>
     /// The subject line of the e-mail message.
     /// </value>
     /// <remarks>
     /// <para>
     /// The subject line of the e-mail message.
     /// </para>
     /// </remarks>
     public string Subject
     {
       get { return m_subject; }
       set { m_subject = value; }
     }

     /// <summary>
     /// Gets or sets the name of the SMTP relay mail server to use to send
     /// the e-mail messages.
     /// </summary>
     /// <value>
     /// The name of the e-mail relay server. If SmtpServer is not set, the
     /// name of the local SMTP server is used.
     /// </value>
     /// <remarks>
     /// <para>
     /// The name of the e-mail relay server. If SmtpServer is not set, the
     /// name of the local SMTP server is used.
     /// </para>
     /// </remarks>
     public string SmtpHost
     {
       get { return m_smtpHost; }
       set { m_smtpHost = value; }
     }

     /// <summary>
     /// Obsolete
     /// </summary>
     /// <remarks>
     /// Use the BufferingAppenderSkeleton Fix methods instead
     /// </remarks>
     /// <remarks>
     /// <para>
     /// Obsolete property.
     /// </para>
     /// </remarks>
     [Obsolete("Use the BufferingAppenderSkeleton Fix methods")]
     public bool LocationInfo
     {
       get { return false; }
       set {; }
     }

     /// <summary>
     /// The mode to use to authentication with the SMTP server
     /// </summary>
     /// <remarks>
     /// <note type="caution">Authentication is only available on the MS .NET 1.1 runtime.</note>
     /// <para>
     /// Valid Authentication mode values are: <see cref="SmtpAuthentication.None"/>,
     /// <see cref="SmtpAuthentication.Basic"/>, and <see cref="SmtpAuthentication.Ntlm"/>.
     /// The default value is <see cref="SmtpAuthentication.None"/>. When using
     /// <see cref="SmtpAuthentication.Basic"/> you must specify the <see cref="Username"/>
     /// and <see cref="Password"/> to use to authenticate.
     /// When using <see cref="SmtpAuthentication.Ntlm"/> the Windows credentials for the current
     /// thread, if impersonating, or the process will be used to authenticate.
     /// </para>
     /// </remarks>
     public SmtpAuthentication Authentication
     {
       get { return m_authentication; }
       set { m_authentication = value; }
     }

     /// <summary>
     /// The username to use to authenticate with the SMTP server
     /// </summary>
     /// <remarks>
     /// <note type="caution">Authentication is only available on the MS .NET 1.1 runtime.</note>
     /// <para>
     /// A <see cref="Username"/> and <see cref="Password"/> must be specified when
     /// <see cref="Authentication"/> is set to <see cref="SmtpAuthentication.Basic"/>,
     /// otherwise the username will be ignored.
     /// </para>
     /// </remarks>
     public string Username
     {
       get { return m_username; }
       set { m_username = value; }
     }

     /// <summary>
     /// The password to use to authenticate with the SMTP server
     /// </summary>
     /// <remarks>
     /// <note type="caution">Authentication is only available on the MS .NET 1.1 runtime.</note>
     /// <para>
     /// A <see cref="Username"/> and <see cref="Password"/> must be specified when
     /// <see cref="Authentication"/> is set to <see cref="SmtpAuthentication.Basic"/>,
     /// otherwise the password will be ignored.
     /// </para>
     /// </remarks>
     public string Password
     {
       get { return m_password; }
       set { m_password = value; }
     }

     /// <summary>
     /// The port on which the SMTP server is listening
     /// </summary>
     /// <remarks>
     /// <note type="caution">Server Port is only available on the MS .NET 1.1 runtime.</note>
     /// <para>
     /// The port on which the SMTP server is listening. The default
     /// port is <c>25</c>. The Port can only be changed when running on
     /// the MS .NET 1.1 runtime.
     /// </para>
     /// </remarks>
     public int Port
     {
       get { return m_port; }
       set { m_port = value; }
     }

     /// <summary>
     /// Gets or sets the priority of the e-mail message
     /// </summary>
     /// <value>
     /// One of the <see cref="MailPriority"/> values.
     /// </value>
     /// <remarks>
     /// <para>
     /// Sets the priority of the e-mails generated by this
     /// appender. The default priority is <see cref="MailPriority.Normal"/>.
     /// </para>
     /// <para>
     /// If you are using this appender to report errors then
     /// you may want to set the priority to <see cref="MailPriority.High"/>.
     /// </para>
     /// </remarks>
     public MailPriority Priority
     {
       get { return m_mailPriority; }
       set { m_mailPriority = value; }
     }

     /// <summary>
     /// Enable or disable use of SSL when sending e-mail message
     /// </summary>
     /// <remarks>
     /// This is available on MS .NET 2.0 runtime and higher
     /// </remarks>
     public bool EnableSsl
     {
       get { return m_enableSsl; }
       set { m_enableSsl = value; }
     }

     /// <summary>
     /// Gets or sets the reply-to e-mail address.
     /// </summary>
     /// <remarks>
     /// This is available on MS .NET 2.0 runtime and higher
     /// </remarks>
     public string ReplyTo
     {
       get { return m_replyTo; }
       set { m_replyTo = value; }
     }

     /// <summary>
     /// Gets or sets the subject encoding to be used.
     /// </summary>
     /// <remarks>
     /// The default encoding is the operating system's current ANSI codepage.
     /// </remarks>
     public Encoding SubjectEncoding
     {
       get { return m_subjectEncoding; }
       set { m_subjectEncoding = value; }
     }

     /// <summary>
     /// Gets or sets the body encoding to be used.
     /// </summary>
     /// <remarks>
     /// The default encoding is the operating system's current ANSI codepage.
     /// </remarks>
     public Encoding BodyEncoding
     {
       get { return m_bodyEncoding; }
       set { m_bodyEncoding = value; }
     }

     #endregion // Public Instance Properties

     #region Override implementation of BufferingAppenderSkeleton

     /// <summary>
     /// Sends the contents of the cyclic buffer as an e-mail message.
     /// </summary>
     /// <param name="events">The logging events to send.</param>
     protected override void SendBuffer(LoggingEvent[] events)
     {
       // Note: this code already owns the monitor for this
       // appender. This frees us from needing to synchronize again.
       try
       {
         using StringWriter writer = new StringWriter(System.Globalization.CultureInfo.InvariantCulture);

         string t = Layout.Header;
         if (t != null)
         {
           writer.Write(t);
         }

         for (int i = 0; i < events.Length; i++)
         {
           // Render the event and append the text to the buffer
           RenderLoggingEvent(writer, events[i]);
         }

         t = Layout.Footer;
         if (t != null)
         {
           writer.Write(t);
         }

         SendEmail(writer.ToString());
       }
       catch (Exception e)
       {
         ErrorHandler.Error("Error occurred while sending e-mail notification.", e);
       }
     }

     #endregion // Override implementation of BufferingAppenderSkeleton

     #region Override implementation of AppenderSkeleton

     /// <summary>
     /// This appender requires a <see cref="Layout"/> to be set.
     /// </summary>
     /// <value><c>true</c></value>
     /// <remarks>
     /// <para>
     /// This appender requires a <see cref="Layout"/> to be set.
     /// </para>
     /// </remarks>
     protected override bool RequiresLayout
     {
       get { return true; }
     }

     #endregion // Override implementation of AppenderSkeleton

     #region Protected Methods

     /// <summary>
     /// Send the email message
     /// </summary>
     /// <param name="messageBody">the body text to include in the mail</param>
     protected virtual void SendEmail(string messageBody)
     {
       // .NET 2.0 has a new API for SMTP email System.Net.Mail
       // This API supports credentials and multiple hosts correctly.
       // The old API is deprecated.

       // Create and configure the smtp client
       using SmtpClient smtpClient = new SmtpClient();
       if (!String.IsNullOrEmpty(m_smtpHost))
       {
         smtpClient.Host = m_smtpHost;
       }
       smtpClient.Port = m_port;
       smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
       smtpClient.EnableSsl = m_enableSsl;

       if (m_authentication == SmtpAuthentication.Basic)
       {
         // Perform basic authentication
         smtpClient.Credentials = new System.Net.NetworkCredential(m_username, m_password);
       }
       else if (m_authentication == SmtpAuthentication.Ntlm)
       {
         // Perform integrated authentication (NTLM)
         smtpClient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;
       }

       using (MailMessage mailMessage = new MailMessage())
       {
         mailMessage.Body = messageBody;
         mailMessage.BodyEncoding = m_bodyEncoding;
         mailMessage.From = new MailAddress(m_from);
         mailMessage.To.Add(m_to);
         if (!String.IsNullOrEmpty(m_cc))
         {
           mailMessage.CC.Add(m_cc);
         }
         if (!String.IsNullOrEmpty(m_bcc))
         {
           mailMessage.Bcc.Add(m_bcc);
         }
         if (!String.IsNullOrEmpty(m_replyTo))
         {
           mailMessage.ReplyToList.Add(new MailAddress(m_replyTo));
         }
         mailMessage.Subject = m_subject;
         mailMessage.SubjectEncoding = m_subjectEncoding;
         mailMessage.Priority = m_mailPriority;

         // TODO: Consider using SendAsync to send the message without blocking. This would be a change in
         // behaviour compared to .NET 1.x. We would need a SendCompletedCallback to log errors.
         smtpClient.Send(mailMessage);
       }
     }

     #endregion // Protected Methods

     #region Private Instance Fields

     private string m_to;
     private string m_cc;
     private string m_bcc;
     private string m_from;
     private string m_subject;
     private string m_smtpHost;
     private Encoding m_subjectEncoding = Encoding.UTF8;
     private Encoding m_bodyEncoding = Encoding.UTF8;

     // authentication fields
     private SmtpAuthentication m_authentication = SmtpAuthentication.None;
     private string m_username;
     private string m_password;

     // server port, default port 25
     private int m_port = 25;

     private MailPriority m_mailPriority = MailPriority.Normal;

     private bool m_enableSsl = false;
     private string m_replyTo;

     #endregion // Private Instance Fields

     #region SmtpAuthentication Enum

     /// <summary>
     /// Values for the <see cref="SmtpAppender.Authentication"/> property.
     /// </summary>
     /// <remarks>
     /// <para>
     /// SMTP authentication modes.
     /// </para>
     /// </remarks>
     public enum SmtpAuthentication
     {
       /// <summary>
       /// No authentication
       /// </summary>
       None,

       /// <summary>
       /// Basic authentication.
       /// </summary>
       /// <remarks>
       /// Requires a username and password to be supplied
       /// </remarks>
       Basic,

       /// <summary>
       /// Integrated authentication
       /// </summary>
       /// <remarks>
       /// Uses the Windows credentials from the current thread or process to authenticate.
       /// </remarks>
       Ntlm
     }

     #endregion // SmtpAuthentication Enum

     private static readonly char[] ADDRESS_DELIMITERS = new char[] { ',', ';' };

     /// <summary>
     ///   trims leading and trailing commas or semicolons
     /// </summary>
     private static string MaybeTrimSeparators(string s)
     {
       return string.IsNullOrEmpty(s) ? s : s.Trim(ADDRESS_DELIMITERS);
     }
   }
 }
	#region Apache License
	//
	// Licensed to the Apache Software Foundation (ASF) under one or more
	// contributor license agreements. See the NOTICE file distributed with
	// this work for additional information regarding copyright ownership.
	// The ASF licenses this file to you under the Apache License, Version 2.0
	// (the "License"); you may not use this file except in compliance with
	// the License. You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.
	//
	#endregion

	using System;
	using System.IO;
	using System.Text;

	using System.Net.Mail;
	using log4net.Core;

	namespace log4net.Appender
	{
	/// <summary>
	/// Send an e-mail when a specific logging event occurs, typically on errors
	/// or fatal errors.
	/// </summary>
	/// <remarks>
	/// <para>
	/// The number of logging events delivered in this e-mail depend on
	/// the value of <see cref="BufferingAppenderSkeleton.BufferSize"/> option. The
	/// <see cref="SmtpAppender"/> keeps only the last
	/// <see cref="BufferingAppenderSkeleton.BufferSize"/> logging events in its
	/// cyclic buffer. This keeps memory requirements at a reasonable level while
	/// still delivering useful application context.
	/// </para>
	/// <note type="caution">
	/// Authentication and setting the server Port are only available on the MS .NET 1.1 runtime.
	/// For these features to be enabled you need to ensure that you are using a version of
	/// the log4net assembly that is built against the MS .NET 1.1 framework and that you are
	/// running the your application on the MS .NET 1.1 runtime. On all other platforms only sending
	/// unauthenticated messages to a server listening on port 25 (the default) is supported.
	/// </note>
	/// <para>
	/// Authentication is supported by setting the <see cref="Authentication"/> property to
	/// either <see cref="SmtpAuthentication.Basic"/> or <see cref="SmtpAuthentication.Ntlm"/>.
	/// If using <see cref="SmtpAuthentication.Basic"/> authentication then the <see cref="Username"/>
	/// and <see cref="Password"/> properties must also be set.
	/// </para>
	/// <para>
	/// To set the SMTP server port use the <see cref="Port"/> property. The default port is 25.
	/// </para>
	/// </remarks>
	/// <author>Nicko Cadell</author>
	/// <author>Gert Driesen</author>
	public class SmtpAppender : BufferingAppenderSkeleton
	{
	#region Public Instance Constructors

	/// <summary>
	/// Default constructor
	/// </summary>
	/// <remarks>
	/// <para>
	/// Default constructor
	/// </para>
	/// </remarks>
	public SmtpAppender()
	{
	}

	#endregion // Public Instance Constructors

	#region Public Instance Properties

	/// <summary>
	/// Gets or sets a comma- or semicolon-delimited list of recipient e-mail addresses (use semicolon on .NET 1.1 and comma for later versions).
	/// </summary>
	/// <value>
	/// <para>
	/// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
	/// </para>
	/// <para>
	/// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
	/// </para>
	/// </value>
	/// <remarks>
	/// <para>
	/// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
	/// </para>
	/// <para>
	/// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
	/// </para>
	/// </remarks>
	public string To
	{
	get { return m_to; }
	set { m_to = MaybeTrimSeparators(value); }
	}

	/// <summary>
	/// Gets or sets a comma- or semicolon-delimited list of recipient e-mail addresses
	/// that will be carbon copied (use semicolon on .NET 1.1 and comma for later versions).
	/// </summary>
	/// <value>
	/// <para>
	/// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
	/// </para>
	/// <para>
	/// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
	/// </para>
	/// </value>
	/// <remarks>
	/// <para>
	/// For .NET 1.1 (System.Web.Mail): A semicolon-delimited list of e-mail addresses.
	/// </para>
	/// <para>
	/// For .NET 2.0 (System.Net.Mail): A comma-delimited list of e-mail addresses.
	/// </para>
	/// </remarks>
	public string Cc
	{
	get { return m_cc; }
	set { m_cc = MaybeTrimSeparators(value); }
	}

	/// <summary>
	/// Gets or sets a semicolon-delimited list of recipient e-mail addresses
	/// that will be blind carbon copied.
	/// </summary>
	/// <value>
	/// A semicolon-delimited list of e-mail addresses.
	/// </value>
	/// <remarks>
	/// <para>
	/// A semicolon-delimited list of recipient e-mail addresses.
	/// </para>
	/// </remarks>
	public string Bcc
	{
	get { return m_bcc; }
	set { m_bcc = MaybeTrimSeparators(value); }
	}

	/// <summary>
	/// Gets or sets the e-mail address of the sender.
	/// </summary>
	/// <value>
	/// The e-mail address of the sender.
	/// </value>
	/// <remarks>
	/// <para>
	/// The e-mail address of the sender.
	/// </para>
	/// </remarks>
	public string From
	{
	get { return m_from; }
	set { m_from = value; }
	}

	/// <summary>
	/// Gets or sets the subject line of the e-mail message.
	/// </summary>
	/// <value>
	/// The subject line of the e-mail message.
	/// </value>
	/// <remarks>
	/// <para>
	/// The subject line of the e-mail message.
	/// </para>
	/// </remarks>
	public string Subject
	{
	get { return m_subject; }
	set { m_subject = value; }
	}

	/// <summary>
	/// Gets or sets the name of the SMTP relay mail server to use to send
	/// the e-mail messages.
	/// </summary>
	/// <value>
	/// The name of the e-mail relay server. If SmtpServer is not set, the
	/// name of the local SMTP server is used.
	/// </value>
	/// <remarks>
	/// <para>
	/// The name of the e-mail relay server. If SmtpServer is not set, the
	/// name of the local SMTP server is used.
	/// </para>
	/// </remarks>
	public string SmtpHost
	{
	get { return m_smtpHost; }
	set { m_smtpHost = value; }
	}

	/// <summary>
	/// Obsolete
	/// </summary>
	/// <remarks>
	/// Use the BufferingAppenderSkeleton Fix methods instead
	/// </remarks>
	/// <remarks>
	/// <para>
	/// Obsolete property.
	/// </para>
	/// </remarks>
	[Obsolete("Use the BufferingAppenderSkeleton Fix methods")]
	public bool LocationInfo
	{
	get { return false; }
	set {; }
	}

	/// <summary>
	/// The mode to use to authentication with the SMTP server
	/// </summary>
	/// <remarks>
	/// <note type="caution">Authentication is only available on the MS .NET 1.1 runtime.</note>
	/// <para>
	/// Valid Authentication mode values are: <see cref="SmtpAuthentication.None"/>,
	/// <see cref="SmtpAuthentication.Basic"/>, and <see cref="SmtpAuthentication.Ntlm"/>.
	/// The default value is <see cref="SmtpAuthentication.None"/>. When using
	/// <see cref="SmtpAuthentication.Basic"/> you must specify the <see cref="Username"/>
	/// and <see cref="Password"/> to use to authenticate.
	/// When using <see cref="SmtpAuthentication.Ntlm"/> the Windows credentials for the current
	/// thread, if impersonating, or the process will be used to authenticate.
	/// </para>
	/// </remarks>
	public SmtpAuthentication Authentication
	{
	get { return m_authentication; }
	set { m_authentication = value; }
	}

	/// <summary>
	/// The username to use to authenticate with the SMTP server
	/// </summary>
	/// <remarks>
	/// <note type="caution">Authentication is only available on the MS .NET 1.1 runtime.</note>
	/// <para>
	/// A <see cref="Username"/> and <see cref="Password"/> must be specified when
	/// <see cref="Authentication"/> is set to <see cref="SmtpAuthentication.Basic"/>,
	/// otherwise the username will be ignored.
	/// </para>
	/// </remarks>
	public string Username
	{
	get { return m_username; }
	set { m_username = value; }
	}

	/// <summary>
	/// The password to use to authenticate with the SMTP server
	/// </summary>
	/// <remarks>
	/// <note type="caution">Authentication is only available on the MS .NET 1.1 runtime.</note>
	/// <para>
	/// A <see cref="Username"/> and <see cref="Password"/> must be specified when
	/// <see cref="Authentication"/> is set to <see cref="SmtpAuthentication.Basic"/>,
	/// otherwise the password will be ignored.
	/// </para>
	/// </remarks>
	public string Password
	{
	get { return m_password; }
	set { m_password = value; }
	}

	/// <summary>
	/// The port on which the SMTP server is listening
	/// </summary>
	/// <remarks>
	/// <note type="caution">Server Port is only available on the MS .NET 1.1 runtime.</note>
	/// <para>
	/// The port on which the SMTP server is listening. The default
	/// port is <c>25</c>. The Port can only be changed when running on
	/// the MS .NET 1.1 runtime.
	/// </para>
	/// </remarks>
	public int Port
	{
	get { return m_port; }
	set { m_port = value; }
	}

	/// <summary>
	/// Gets or sets the priority of the e-mail message
	/// </summary>
	/// <value>
	/// One of the <see cref="MailPriority"/> values.
	/// </value>
	/// <remarks>
	/// <para>
	/// Sets the priority of the e-mails generated by this
	/// appender. The default priority is <see cref="MailPriority.Normal"/>.
	/// </para>
	/// <para>
	/// If you are using this appender to report errors then
	/// you may want to set the priority to <see cref="MailPriority.High"/>.
	/// </para>
	/// </remarks>
	public MailPriority Priority
	{
	get { return m_mailPriority; }
	set { m_mailPriority = value; }
	}

	/// <summary>
	/// Enable or disable use of SSL when sending e-mail message
	/// </summary>
	/// <remarks>
	/// This is available on MS .NET 2.0 runtime and higher
	/// </remarks>
	public bool EnableSsl
	{
	get { return m_enableSsl; }
	set { m_enableSsl = value; }
	}

	/// <summary>
	/// Gets or sets the reply-to e-mail address.
	/// </summary>
	/// <remarks>
	/// This is available on MS .NET 2.0 runtime and higher
	/// </remarks>
	public string ReplyTo
	{
	get { return m_replyTo; }
	set { m_replyTo = value; }
	}

	/// <summary>
	/// Gets or sets the subject encoding to be used.
	/// </summary>
	/// <remarks>
	/// The default encoding is the operating system's current ANSI codepage.
	/// </remarks>
	public Encoding SubjectEncoding
	{
	get { return m_subjectEncoding; }
	set { m_subjectEncoding = value; }
	}

	/// <summary>
	/// Gets or sets the body encoding to be used.
	/// </summary>
	/// <remarks>
	/// The default encoding is the operating system's current ANSI codepage.
	/// </remarks>
	public Encoding BodyEncoding
	{
	get { return m_bodyEncoding; }
	set { m_bodyEncoding = value; }
	}

	#endregion // Public Instance Properties

	#region Override implementation of BufferingAppenderSkeleton

	/// <summary>
	/// Sends the contents of the cyclic buffer as an e-mail message.
	/// </summary>
	/// <param name="events">The logging events to send.</param>
	protected override void SendBuffer(LoggingEvent[] events)
	{
	// Note: this code already owns the monitor for this
	// appender. This frees us from needing to synchronize again.
	try
	{
	using StringWriter writer = new StringWriter(System.Globalization.CultureInfo.InvariantCulture);

	string t = Layout.Header;
	if (t != null)
	{
	writer.Write(t);
	}

	for (int i = 0; i < events.Length; i++)
	{
	// Render the event and append the text to the buffer
	RenderLoggingEvent(writer, events[i]);
	}

	t = Layout.Footer;
	if (t != null)
	{
	writer.Write(t);
	}

	SendEmail(writer.ToString());
	}
	catch (Exception e)
	{
	ErrorHandler.Error("Error occurred while sending e-mail notification.", e);
	}
	}

	#endregion // Override implementation of BufferingAppenderSkeleton

	#region Override implementation of AppenderSkeleton

	/// <summary>
	/// This appender requires a <see cref="Layout"/> to be set.
	/// </summary>
	/// <value><c>true</c></value>
	/// <remarks>
	/// <para>
	/// This appender requires a <see cref="Layout"/> to be set.
	/// </para>
	/// </remarks>
	protected override bool RequiresLayout
	{
	get { return true; }
	}

	#endregion // Override implementation of AppenderSkeleton

	#region Protected Methods

	/// <summary>
	/// Send the email message
	/// </summary>
	/// <param name="messageBody">the body text to include in the mail</param>
	protected virtual void SendEmail(string messageBody)
	{
	// .NET 2.0 has a new API for SMTP email System.Net.Mail
	// This API supports credentials and multiple hosts correctly.
	// The old API is deprecated.

	// Create and configure the smtp client
	using SmtpClient smtpClient = new SmtpClient();
	if (!String.IsNullOrEmpty(m_smtpHost))
	{
	smtpClient.Host = m_smtpHost;
	}
	smtpClient.Port = m_port;
	smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
	smtpClient.EnableSsl = m_enableSsl;

	if (m_authentication == SmtpAuthentication.Basic)
	{
	// Perform basic authentication
	smtpClient.Credentials = new System.Net.NetworkCredential(m_username, m_password);
	}
	else if (m_authentication == SmtpAuthentication.Ntlm)
	{
	// Perform integrated authentication (NTLM)
	smtpClient.Credentials = System.Net.CredentialCache.DefaultNetworkCredentials;
	}

	using (MailMessage mailMessage = new MailMessage())
	{
	mailMessage.Body = messageBody;
	mailMessage.BodyEncoding = m_bodyEncoding;
	mailMessage.From = new MailAddress(m_from);
	mailMessage.To.Add(m_to);
	if (!String.IsNullOrEmpty(m_cc))
	{
	mailMessage.CC.Add(m_cc);
	}
	if (!String.IsNullOrEmpty(m_bcc))
	{
	mailMessage.Bcc.Add(m_bcc);
	}
	if (!String.IsNullOrEmpty(m_replyTo))
	{
	mailMessage.ReplyToList.Add(new MailAddress(m_replyTo));
	}
	mailMessage.Subject = m_subject;
	mailMessage.SubjectEncoding = m_subjectEncoding;
	mailMessage.Priority = m_mailPriority;

	// TODO: Consider using SendAsync to send the message without blocking. This would be a change in
	// behaviour compared to .NET 1.x. We would need a SendCompletedCallback to log errors.
	smtpClient.Send(mailMessage);
	}
	}

	#endregion // Protected Methods

	#region Private Instance Fields

	private string m_to;
	private string m_cc;
	private string m_bcc;
	private string m_from;
	private string m_subject;
	private string m_smtpHost;
	private Encoding m_subjectEncoding = Encoding.UTF8;
	private Encoding m_bodyEncoding = Encoding.UTF8;

	// authentication fields
	private SmtpAuthentication m_authentication = SmtpAuthentication.None;
	private string m_username;
	private string m_password;

	// server port, default port 25
	private int m_port = 25;

	private MailPriority m_mailPriority = MailPriority.Normal;

	private bool m_enableSsl = false;
	private string m_replyTo;

	#endregion // Private Instance Fields

	#region SmtpAuthentication Enum

	/// <summary>
	/// Values for the <see cref="SmtpAppender.Authentication"/> property.
	/// </summary>
	/// <remarks>
	/// <para>
	/// SMTP authentication modes.
	/// </para>
	/// </remarks>
	public enum SmtpAuthentication
	{
	/// <summary>
	/// No authentication
	/// </summary>
	None,

	/// <summary>
	/// Basic authentication.
	/// </summary>
	/// <remarks>
	/// Requires a username and password to be supplied
	/// </remarks>
	Basic,

	/// <summary>
	/// Integrated authentication
	/// </summary>
	/// <remarks>
	/// Uses the Windows credentials from the current thread or process to authenticate.
	/// </remarks>
	Ntlm
	}

	#endregion // SmtpAuthentication Enum

	private static readonly char[] ADDRESS_DELIMITERS = new char[] { ',', ';' };

	/// <summary>
	/// trims leading and trailing commas or semicolons
	/// </summary>
	private static string MaybeTrimSeparators(string s)
	{
	return string.IsNullOrEmpty(s) ? s : s.Trim(ADDRESS_DELIMITERS);
	}
	}
	}