diff --git a/src/log4net/Appender/SmtpAppender.cs b/src/log4net/Appender/SmtpAppender.cs
index c323415a..81d9fca7 100644
--- a/src/log4net/Appender/SmtpAppender.cs
+++ b/src/log4net/Appender/SmtpAppender.cs
@@ -436,7 +436,9 @@ protected virtual void SendEmail(string messageBody)
       // The old API is deprecated.
 
       // Create and configure the smtp client
+#pragma warning disable CS0618 // Type or member is obsolete
       using SmtpClient smtpClient = new SmtpClient();
+#pragma warning restore CS0618 // Type or member is obsolete
       if (!String.IsNullOrEmpty(m_smtpHost))
       {
         smtpClient.Host = m_smtpHost;