Exceptions cause error-level logging in addition to rethrowing the exception, but should just include the message in a custom exception

[SantoshDeepak1]

When the SMTP credentials are wrong and at the time of sending email library logs the error itself instead propagating to caller.

org.simplejavamail.mailer.internal.AbstractProxyServerSyncingClosure

Failed to send email:
736007253.1.1625220323405@LP-IND-PUN-59.SSGCORP.local

[bbottema]

I'm not sure what you mean, but the exception is thrown again:

[bbottema]

Closing until new information comes up.

[martonsz]

@bbottema I'm having the same issue using version 7.0.1

This issue creates unnecessary error reports that is created for error level logs in our application.

Here is an example to reproduce this. You just have to set an unknown host:

package mail;

import org.simplejavamail.MailException;
import org.simplejavamail.api.email.Email;
import org.simplejavamail.api.mailer.Mailer;
import org.simplejavamail.api.mailer.config.TransportStrategy;
import org.simplejavamail.email.EmailBuilder;
import org.simplejavamail.mailer.MailerBuilder;

public class SimpleMailTest {

	public static void main(String[] args) {

		try {
			String host = "foo.fooexample.com";
			int port = 587;
			String username = "username";
			String password = "password";

			Mailer mailer = MailerBuilder.withSMTPServer(host, port, username, password)
					.withTransportStrategy(TransportStrategy.SMTP_TLS)
					.withDebugLogging(false)
					.buildMailer();
			// mailer.testConnection();

			Email email = EmailBuilder.startingBlank()
					.from("Michel Baker", "m.baker@mbakery.com")
					.to("mom", "jean.baker@hotmail.com")
					.to("dad", "StevenOakly1963@hotmail.com")
					.withSubject("My Bakery is finally open!")
					.withPlainText("Mom, Dad. We did the opening ceremony of our bakery!!!")
					.buildEmail();

			mailer.sendMail(email, false);

		} catch (MailException e) {
			System.err.println("########################## Caught MailException");
			e.printStackTrace();
		} catch (Throwable e) {
			System.err.println("~~~~~~~~~~~~~~~~~~~~~~~~~~ Caught Throwable");
			e.printStackTrace();
		}
	}
}

Here is the output. Notice that AbstractProxyServerSyncingClosure logs an error before the Catch stage

2022-01-25 11:06:12.212 ERROR o.s.m.i.AbstractProxyServerSyncingClosure [main] Failed to send email:
<1373810119.0.1643105172187@WIN10PC>
########################## Caught MailException
org.simplejavamail.mailer.internal.MailerException: Third party error
	at org.simplejavamail.mailer.internal.SendMailClosure.executeClosure(SendMailClosure.java:91)
	at org.simplejavamail.mailer.internal.AbstractProxyServerSyncingClosure.run(AbstractProxyServerSyncingClosure.java:56)
	at org.simplejavamail.mailer.internal.MailerImpl.sendMail(MailerImpl.java:345)
	at mail.SimpleMailTest.main(SimpleMailTest.java:34)
Caused by: com.sun.mail.util.MailConnectException: Couldn't connect to host, port: foo.fooexample.com, 587; timeout 60000;
  nested exception is:
	java.net.UnknownHostException: foo.fooexample.com
	at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2210)
	at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:722)
	at jakarta.mail.Service.connect(Service.java:364)
	at jakarta.mail.Service.connect(Service.java:222)
	at jakarta.mail.Service.connect(Service.java:171)
	at org.simplejavamail.mailer.internal.util.TransportRunner.runOnSessionTransport(TransportRunner.java:67)
	at org.simplejavamail.mailer.internal.util.TransportRunner.sendMessage(TransportRunner.java:47)
	at org.simplejavamail.mailer.internal.SendMailClosure.executeClosure(SendMailClosure.java:82)
	... 3 more
Caused by: java.net.UnknownHostException: foo.fooexample.com
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184)
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:607)
	at com.sun.mail.util.WriteTimeoutSocket.connect(WriteTimeoutSocket.java:91)
	at com.sun.mail.util.SocketFetcher.createSocket(SocketFetcher.java:333)
	at com.sun.mail.util.SocketFetcher.getSocket(SocketFetcher.java:214)
	at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2160)
	... 10 more

[bbottema]

I still don't see the problem. The library does not log the actual error and does propagate it to the caller. The only error-level detail the library logs in addition to that is the following:

12:09:39 [main] ERROR AbstractProxyServerSyncingClosure - Failed to send email:
1579280783.0.1643108979695@Cypher.mshome.net

Is this what you are referring to?

[martonsz]

yes. It is that extra error log line I am referring to.

In my example it is:

2022-01-25 11:06:12.212 ERROR o.s.m.i.AbstractProxyServerSyncingClosure [main] Failed to send email:
<1373810119.0.1643105172187@WIN10PC>

[bbottema]

I agree, it is not needed if we're rethrowing the exception anyway. Might as well wrap both the cause and the logged message in new exception.

[bbottema]

Fix released in 7.0.2