Adding timeouts to SMTP transport sockets for issue bbottema#85

Author: amanteaux

src/main/java/org/simplejavamail/mailer/Mailer.java

@@ -10,6 +10,8 @@
 import org.simplejavamail.mailer.config.TransportStrategy;
 import org.simplejavamail.mailer.internal.mailsender.MailSender;
 import org.simplejavamail.converter.internal.mimemessage.MimeMessageHelper;
+import org.simplejavamail.util.ConfigLoader;
+import org.simplejavamail.util.ConfigLoader.Property;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -83,6 +85,12 @@ public class Mailer {
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(Mailer.class);
 
+	/**
+	 * the default maximum timeout value for the transport socket is {@value #DEFAULT_SEND_MAIL_SOCKET_TIMEOUT}
+	 * milliseconds. Can be overridden from a config file or through System variable.
+	 */
+	private static final String DEFAULT_SEND_MAIL_SOCKET_TIMEOUT = "60000";
+
 	private final MailSender mailSender;
 
 	/**
@@ -229,6 +237,14 @@ public static Session createMailSession(final ServerConfig serverConfig, final T
 		props.put(transportStrategy.propertyNameHost(), serverConfig.getHost());
 		props.put(transportStrategy.propertyNamePort(), String.valueOf(serverConfig.getPort()));
 
+		// socket timeouts handling
+		String sendMailTimeoutInMillis = ConfigLoader.valueOrProperty(
+			null, Property.DEFAULT_SEND_MAIL_TIMEOUT_IN_MILLIS, DEFAULT_SEND_MAIL_SOCKET_TIMEOUT
+		);
+		props.put("mail.smtp.connectiontimeout", sendMailTimeoutInMillis);
+		props.put("mail.smtp.timeout", sendMailTimeoutInMillis);
+		props.put("mail.smtp.writetimeout", sendMailTimeoutInMillis);
+
 		if (serverConfig.getUsername() != null) {
 			props.put(transportStrategy.propertyNameUsername(), serverConfig.getUsername());
 		}

src/main/java/org/simplejavamail/mailer/internal/mailsender/MailSender.java

@@ -168,7 +168,7 @@ public void run() {
 					try {
 						sendMailClosure(session, email);
 					} catch (Exception e) {
-						LOGGER.trace("could not send email '{}' to {}", email.getSubject(), email.getRecipients(), e);
+						LOGGER.error("could not send email {}", email, e);
 					}
 				}
 			});

src/main/java/org/simplejavamail/util/ConfigLoader.java

@@ -94,6 +94,7 @@ public enum Property {
 		DEFAULT_BCC_NAME("simplejavamail.defaults.bcc.name"),
 		DEFAULT_BCC_ADDRESS("simplejavamail.defaults.bcc.address"),
 		DEFAULT_POOL_SIZE("simplejavamail.defaults.poolsize"),
+		DEFAULT_SEND_MAIL_TIMEOUT_IN_MILLIS("simplejavamail.defaults.sendmailtimeoutinmillis"),
 		TRANSPORT_MODE_LOGGING_ONLY("simplejavamail.transport.mode.logging.only");
 
 		private final String key;