[ENHANCEMENT] Dedicated debug logs for significant SMTP details

Failing hooks are also logged at INFO

Author: chibenwa

protocols/smtp/src/main/java/org/apache/james/protocols/smtp/core/HeloCmdHandler.java

@@ -23,6 +23,7 @@
 
 import jakarta.inject.Inject;
 
+import org.apache.commons.lang3.StringUtils;
 import org.apache.james.metrics.api.MetricFactory;
 import org.apache.james.protocols.api.ProtocolSession;
 import org.apache.james.protocols.api.ProtocolSession.State;
@@ -82,6 +83,8 @@ protected Response doCoreCmd(SMTPSession session, String command,
         response.append(session.getConfiguration().getHelloName()).append(
                 " Hello ").append(parameters).append(" [").append(
                 session.getRemoteAddress().getAddress().getHostAddress()).append("])");
+
+        LOGGER.debug("HELO {} {}", StringUtils.abbreviate(command, 80), StringUtils.abbreviate(parameters, 80));
         return new SMTPResponse(SMTPRetCode.MAIL_OK, response);
     }
 

protocols/smtp/src/main/java/org/apache/james/protocols/smtp/core/MailCmdHandler.java

@@ -29,6 +29,7 @@
 import jakarta.inject.Inject;
 import jakarta.mail.internet.AddressException;
 
+import org.apache.commons.lang3.StringUtils;
 import org.apache.james.core.MailAddress;
 import org.apache.james.core.MaybeSender;
 import org.apache.james.metrics.api.MetricFactory;
@@ -110,6 +111,8 @@ private Response doMAIL(SMTPSession session) {
             responseBuffer.append(sender.asString());
         }
         responseBuffer.append("> OK");
+
+        LOGGER.debug("MAIL FROM {}", StringUtils.abbreviate(sender.asString(), 80));
         return new SMTPResponse(SMTPRetCode.MAIL_OK, responseBuffer);
     }
 

protocols/smtp/src/main/java/org/apache/james/protocols/smtp/core/QuitCmdHandler.java

@@ -31,21 +31,24 @@
 import org.apache.james.protocols.smtp.dsn.DSNStatus;
 import org.apache.james.protocols.smtp.hook.HookResult;
 import org.apache.james.protocols.smtp.hook.QuitHook;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import com.google.common.collect.ImmutableSet;
 
 /**
  * Handles QUIT command
  */
 public class QuitCmdHandler extends AbstractHookableCmdHandler<QuitHook> {
+    private static final Logger LOGGER = LoggerFactory.getLogger(QuitCmdHandler.class);
 
     /**
      * The name of the command handled by the command handler
      */
     private static final Collection<String> COMMANDS = ImmutableSet.of("QUIT");
 
     private static final Response SYNTAX_ERROR;
-    
+
     static {
         SMTPResponse response = new SMTPResponse(
                 SMTPRetCode.SYNTAX_ERROR_COMMAND_UNRECOGNIZED, DSNStatus
@@ -80,6 +83,8 @@ private Response doQUIT(SMTPSession session, String argument) {
                     " Service closing transmission channel");
             SMTPResponse ret = new SMTPResponse(SMTPRetCode.SYSTEM_QUIT, response);
             ret.setEndSession(true);
+
+            LOGGER.debug("QUIT");
             return ret;
         } else {
             return SYNTAX_ERROR;

protocols/smtp/src/main/java/org/apache/james/protocols/smtp/core/RcptCmdHandler.java

@@ -28,6 +28,7 @@
 
 import jakarta.inject.Inject;
 
+import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.james.core.MailAddress;
 import org.apache.james.core.MaybeSender;
@@ -85,12 +86,14 @@ protected Response doCoreCmd(SMTPSession session, String command, String paramet
         MailAddress recipientAddress = session.getAttachment(CURRENT_RECIPIENT, State.Transaction).orElse(MailAddress.nullSender());
         rcptColl.add(recipientAddress);
         session.setAttachment(SMTPSession.RCPT_LIST, rcptColl, State.Transaction);
+
         StringBuilder response = new StringBuilder();
-        response
-                .append(
-                        DSNStatus.getStatus(DSNStatus.SUCCESS,
-                                DSNStatus.ADDRESS_VALID))
+        String status = DSNStatus.getStatus(DSNStatus.SUCCESS, DSNStatus.ADDRESS_VALID);
+        response.append(status)
                 .append(" Recipient <").append(recipientAddress).append("> OK");
+
+        LOGGER.debug("RCPT TO {}", StringUtils.abbreviate(recipientAddress.asString(), 80));
+
         return new SMTPResponse(SMTPRetCode.MAIL_OK, response);
 
     }

protocols/smtp/src/main/java/org/apache/james/protocols/smtp/core/esmtp/EhloCmdHandler.java

@@ -25,6 +25,7 @@
 
 import jakarta.inject.Inject;
 
+import org.apache.commons.lang3.StringUtils;
 import org.apache.james.metrics.api.MetricFactory;
 import org.apache.james.protocols.api.ProtocolSession.State;
 import org.apache.james.protocols.api.Response;
@@ -95,6 +96,8 @@ private Response doEHLO(SMTPSession session, String argument) {
                 COMMAND_NAME, State.Connection);
 
         processExtensions(session, resp);
+
+        LOGGER.debug("EHLO {}", StringUtils.abbreviate(argument, 80));
 
         return resp;
     }