SMTP doesn't work

[AdriDevelopsThings]

Describe the bug
I configured SMTP (mailcow server) with STARTTLS and the emails are not sent.

To Reproduce

• Use a mailcow server
  Use the following configuration paramenters:
• hostname: mail.example.org
• port: 587
• smtp protocol: smtp
• smtp username: [email protected]
• smtp password: ur password
• e-mail sender: [email protected]
• smtp properties: mail.smtp.starttls.enable=true

Expected behavior
The E-Mail would be sent.

Behavior
I get the following error:

alfio_1  | 22:26:20.052 [scheduling-1] WARN  alfio.manager.NotificationManager - could not send message: 
alfio_1  | org.springframework.mail.MailSendException: Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: mail.adridoesthings.com, port: 587;
alfio_1  |   nested exception is:
alfio_1  |      java.net.ConnectException: Operation timed out (Connection timed out). Failed messages: javax.mail.MessagingException: Could not connect to SMTP host: mail.adridoesthings.com, port: 587;
alfio_1  |   nested exception is:
alfio_1  |      java.net.ConnectException: Operation timed out (Connection timed out)
alfio_1  |      at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:448) ~[spring-context-support-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:361) ~[spring-context-support-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:378) ~[spring-context-support-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:366) ~[spring-context-support-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at alfio.manager.system.SmtpMailer.send(SmtpMailer.java:88) ~[classes/:?]
alfio_1  |      at alfio.manager.system.DefaultMailer.send(DefaultMailer.java:60) ~[classes/:?]
alfio_1  |      at alfio.manager.NotificationManager.sendMessage(NotificationManager.java:349) ~[classes/:?]
alfio_1  |      at alfio.manager.NotificationManager.lambda$processMessage$19(NotificationManager.java:334) ~[classes/:?]
alfio_1  |      at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140) ~[spring-tx-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at alfio.manager.NotificationManager.processMessage(NotificationManager.java:333) ~[classes/:?]
alfio_1  |      at alfio.manager.NotificationManager.lambda$sendWaitingMessages$16(NotificationManager.java:316) ~[classes/:?]
alfio_1  |      at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.DistinctOps$1$2.accept(Unknown Source) ~[?:?]
alfio_1  |      at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.ReferencePipeline$Head.forEach(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.ReferencePipeline$7$1.accept(Unknown Source) ~[?:?]
alfio_1  |      at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
alfio_1  |      at java.util.stream.ReferencePipeline.forEach(Unknown Source) ~[?:?]
alfio_1  |      at alfio.manager.NotificationManager.sendWaitingMessages(NotificationManager.java:316) ~[classes/:?]
alfio_1  |      at alfio.manager.NotificationManager$$FastClassBySpringCGLIB$$3482d7f4.invoke(<generated>) ~[classes/:?]
alfio_1  |      at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:771) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749) ~[spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:366) [spring-tx-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:118) [spring-tx-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) [spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:749) [spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:691) [spring-aop-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at alfio.manager.NotificationManager$$EnhancerBySpringCGLIB$$76407b7.sendWaitingMessages(<generated>) [classes/:?]
alfio_1  |      at alfio.job.Jobs.sendEmails(Jobs.java:103) [classes/:?]
alfio_1  |      at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
alfio_1  |      at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
alfio_1  |      at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
alfio_1  |      at java.lang.reflect.Method.invoke(Unknown Source) ~[?:?]
alfio_1  |      at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) [spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) [spring-context-5.2.5.RELEASE.jar:5.2.5.RELEASE]
alfio_1  |      at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) [?:?]
alfio_1  |      at java.util.concurrent.FutureTask.runAndReset(Unknown Source) [?:?]
alfio_1  |      at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) [?:?]
alfio_1  |      at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:?]
alfio_1  |      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:?]
alfio_1  |      at java.lang.Thread.run(Unknown Source) [?:?]

Alfio Version: latest

Can somebody tell me how to fix the issue? My mailcow server is not broken: When I use thunderbird with port 587 and STARTLS I can send E-Mails.

[cbellone]

Hi, it looks like you have some networking issue (or EGRESS firewall rule) preventing you to access your mailserver

Operation timed out (Connection timed out)

please double check your docker/network configuration

[AdriDevelopsThings]

I checked my network environment.
docker exec -u 0 -it alfio_alfio_1 ping mail.example.prg
I could ping my mailserver from the container.

[cbellone]

If you don't mind I'd like to move this to a discussion, since it's not likely to be an alf.io bug (might be related to the Java Virtual Machine though...)

Not sure if you have the "telnet" command in the docker image anyway can you try something like this

telnet mail.example.org 587

because ping uses another protocol and another port, so the firewall (if any) might be blocking port 587 specifically

[AdriDevelopsThings]

Oh yes you are right. I have my mailserver (mailcow) in a docker container with forwarded port to 0.0.0.0 via docker. But when I want to open port 587 with my public ip from the other docker container (alfio) I cant call it. From the host the port ist available. Do you know what the problem is?

[cbellone]

disclaimer: I've never done something like this with "vanilla" docker. So take these suggestions with a grain of salt.

assuming that all the containers are running on the same host, first of all I'd make sure that all of them are on the same docker network.

here's an interesting article on how you can run multiple containers on the same network: https://www.tutorialworks.com/container-networking/

Once you have the networking configured, you should configure alf.io to call mailcow using its internal IP/alias, instead of using its public dns name.
This way the request shouldn't be routed through different network interfaces, which might be where the firewall is blocking it.

hope this helps