Unable to get smtp to work on docker tag alf.io:2.0-M4-2407

[melancholytron]

Describe the bug
Unable to get smtp to work on docker tag alf.io:2.0-M4-2407

To Reproduce
Under email settings:
SMTP hostname :mail.opentesla.org
SMTP port: 465 (have tried all the usual ports as well)
SMTP Protocol (smtp or smtps) :smtp (Have tried both)
SMTP Username :username@opentesla.org
SMTP Password :fakepassword
E-Mail sender: username@opentesla.org

Expected behavior
I expect it to send an email but doesn't

Screenshots

Desktop (please complete the following information):
Docker, Ubuntu. alf.io:2.0-M4-2407, running through Nginx. Email provider is siteground.

Additional context
I have pinged the mail server from the container and it seems fine but when it tries to send an email i get the following logs:

2024-08-28 15:18:52.792 [pool-4-thread-1] WARN  alfio.manager.NotificationManager - could not send message: 

org.springframework.mail.MailSendException: Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: mail.opentesla.org, port: 465, response: -1. Failed messages: javax.mail.MessagingException: Could not connect to SMTP host: mail.opentesla.org, port: 465, response: -1
	at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:448) ~[spring-context-support-5.3.18.jar:5.3.18]
	at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:361) ~[spring-context-support-5.3.18.jar:5.3.18]
	at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:378) ~[spring-context-support-5.3.18.jar:5.3.18]
	at org.springframework.mail.javamail.JavaMailSenderImpl.send(JavaMailSenderImpl.java:366) ~[spring-context-support-5.3.18.jar:5.3.18]
	at alfio.manager.system.SmtpMailer.send(SmtpMailer.java:95) ~[classes/:?]
	at alfio.manager.system.DefaultMailer.send(DefaultMailer.java:64) ~[classes/:?]
	at alfio.manager.NotificationManager.sendMessage(NotificationManager.java:443) ~[classes/:?]
	at alfio.manager.NotificationManager.lambda$processMessage$18(NotificationManager.java:428) ~[classes/:?]
	at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140) ~[spring-tx-5.3.18.jar:5.3.18]
	at alfio.manager.NotificationManager.processMessage(NotificationManager.java:427) ~[classes/:?]
	at alfio.manager.NotificationManager.lambda$sendWaitingMessages$14(NotificationManager.java:411) ~[classes/:?]
	at java.util.stream.ReferencePipeline$4$1.accept(Unknown Source) ~[?:?]
	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(Unknown Source) ~[?:?]
	at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
	at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(Unknown Source) ~[?:?]
	at java.util.stream.ForEachOps$ForEachOp$OfInt.evaluateSequential(Unknown Source) ~[?:?]
	at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
	at java.util.stream.IntPipeline.forEach(Unknown Source) ~[?:?]
	at java.util.stream.ReferencePipeline$8$1.accept(Unknown Source) ~[?:?]
	at java.util.HashMap$EntrySpliterator.forEachRemaining(Unknown Source) ~[?:?]
	at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[?:?]
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[?:?]
	at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source) ~[?:?]
	at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[?:?]
	at java.util.stream.IntPipeline.reduce(Unknown Source) ~[?:?]
	at java.util.stream.IntPipeline.sum(Unknown Source) ~[?:?]
	at alfio.manager.NotificationManager.sendWaitingMessages(NotificationManager.java:412) ~[classes/:?]
	at alfio.manager.NotificationManager$$FastClassBySpringCGLIB$$3482d7f4.invoke(<generated>) ~[classes/:?]
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.18.jar:5.3.18]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:783) ~[spring-aop-5.3.18.jar:5.3.18]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.18.jar:5.3.18]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.18.jar:5.3.18]
	at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-5.3.18.jar:5.3.18]
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388) ~[spring-tx-5.3.18.jar:5.3.18]
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.18.jar:5.3.18]
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.18.jar:5.3.18]
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.18.jar:5.3.18]
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:698) ~[spring-aop-5.3.18.jar:5.3.18]
	at alfio.manager.NotificationManager$$EnhancerBySpringCGLIB$$e3f4f962.sendWaitingMessages(<generated>) ~[classes/:?]
	at alfio.job.Jobs.sendEmails(Jobs.java:114) ~[classes/:?]
	at jdk.internal.reflect.GeneratedMethodAccessor188.invoke(Unknown Source) ~[?:?]
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[?:?]
	at java.lang.reflect.Method.invoke(Unknown Source) ~[?:?]
	at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) ~[spring-context-5.3.18.jar:5.3.18]
	at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.3.18.jar:5.3.18]
	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?]
	at java.util.concurrent.FutureTask.runAndReset(Unknown Source) ~[?:?]
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) ~[?:?]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) ~[?:?]
	at java.lang.Thread.run(Unknown Source) ~[?:?]
Caused by: javax.mail.MessagingException: Could not connect to SMTP host: mail.opentesla.org, port: 465, response: -1
	at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1949) ~[mail-1.5.0-b01.jar:1.5.0-b01]
	at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:654) ~[mail-1.5.0-b01.jar:1.5.0-b01]
	at javax.mail.Service.connect(Service.java:295) ~[mail-1.5.0-b01.jar:1.5.0-b01]
	at org.springframework.mail.javamail.JavaMailSenderImpl.connectTransport(JavaMailSenderImpl.java:518) ~[spring-context-support-5.3.18.jar:5.3.18]
	at org.springframework.mail.javamail.JavaMailSenderImpl.doSend(JavaMailSenderImpl.java:437) ~[spring-context-support-5.3.18.jar:5.3.18]