adding support for reply-to header

core/src/main/java/hudson/tasks/MailSender.java

@@ -38,6 +38,9 @@ import javax.mail.Transport;
 import javax.mail.internet.InternetAddress;
 import javax.mail.internet.MimeMessage;
 import javax.mail.internet.AddressException;
+
+import org.apache.commons.lang.StringUtils;
+
 import java.io.File;
 import java.io.IOException;
 import java.util.*;
@@ -310,6 +313,11 @@ public class MailSender {
         msg.setContent("", "text/plain");
         msg.setFrom(new InternetAddress(Mailer.descriptor().getAdminAddress()));
         msg.setSentDate(new Date());
+        
+        String replyTo = Mailer.descriptor().getReplyToAddress();
+        if (StringUtils.isNotBlank(replyTo)) {
+            msg.setHeader("Reply-To", replyTo);
+        }
 
         Set<InternetAddress> rcp = new LinkedHashSet<InternetAddress>();
         String defaultSuffix = Mailer.descriptor().getDefaultSuffix();

core/src/main/java/hudson/tasks/Mailer.java

@@ -40,6 +40,14 @@ import hudson.model.UserPropertyDescriptor;
 import hudson.util.FormValidation;
 import hudson.util.Secret;
 
+import org.apache.commons.lang.StringUtils;
+import org.apache.tools.ant.types.selectors.SelectorUtils;
+import org.kohsuke.accmod.Restricted;
+import org.kohsuke.accmod.restrictions.NoExternalUse;
+import org.kohsuke.stapler.QueryParameter;
+import org.kohsuke.stapler.StaplerRequest;
+import org.kohsuke.stapler.export.Exported;
+
 import java.io.File;
 import java.io.IOException;
 import java.net.InetAddress;
@@ -171,6 +179,20 @@ public class Mailer extends Notifier {
          */
         private String adminAddress;
 
+        /**
+         * The e-mail address that Hudson puts to "Reply-To" header in outgoing e-mails.
+         * Null if not configured.
+         */
+        private String replyToAddress;
+
+        public String getReplyToAddress() {
+            return replyToAddress;
+        }
+
+        public void setReplyToAddress(String address) {
+            this.replyToAddress = address;
+        }
+
         /**
          * The SMTP server to use for sending e-mail. Null for default to the environment,
          * which is usually <tt>localhost</tt>.
@@ -450,6 +472,9 @@ public class Mailer extends Notifier {
                 msg.setSubject(Messages.Mailer_TestMail_Subject(++testEmailCount), charset);
                 msg.setText(Messages.Mailer_TestMail_Content(testEmailCount, Jenkins.getInstance().getDisplayName()), charset);
                 msg.setFrom(new InternetAddress(adminAddress));
+                if (StringUtils.isNotBlank(replyToAddress)) {
+                    msg.setHeader("Reply-To", replyToAddress);
+                }
                 msg.setSentDate(new Date());
                 msg.setRecipient(Message.RecipientType.TO, new InternetAddress(sendTestMailTo));