I have tried all of the various SMTP options for mail delivery, however, the server fails to properly send mail regardless of the method I use. It recognizes the method it is attempting to send with, but always fails with an error stating that there is no appropriate protocol.
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.internal.util.concurrent.AsyncOperationHelper$1.run(AsyncOperationHelper.java:75)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:829)
Caused by: javax.mail.MessagingException: Could not convert socket to TLS
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1907)
at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:666)
at javax.mail.Service.connect(Service.java:317)
at javax.mail.Service.connect(Service.java:176)
at javax.mail.Service.connect(Service.java:125)
at org.simplejavamail.mailer.internal.util.TransportRunner.runOnSessionTransport(TransportRunner.java:75)
at org.simplejavamail.mailer.internal.util.TransportRunner.sendMessage(TransportRunner.java:48)
at org.simplejavamail.mailer.internal.SendMailClosure.executeClosure(SendMailClosure.java:82)
... 7 common frames omitted
Caused by: javax.net.ssl.SSLHandshakeException: No appropriate protocol (protocol is disabled or cipher suites are inappropriate)
at java.base/sun.security.ssl.HandshakeContext.<init>(HandshakeContext.java:170)
at java.base/sun.security.ssl.ClientHandshakeContext.<init>(ClientHandshakeContext.java:98)
at java.base/sun.security.ssl.TransportContext.kickstart(TransportContext.java:221)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:443)
at java.base/sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:421)
at com.sun.mail.util.SocketFetcher.configureSSLSocket(SocketFetcher.java:549)
at com.sun.mail.util.SocketFetcher.startTLS(SocketFetcher.java:486)
at com.sun.mail.smtp.SMTPTransport.startTLS(SMTPTransport.java:1902)
... 14 common frames omitted
05:17:06.349 [pool-24-thread-1] WARN c.s.c.c.p.provider.EmailServiceImpl - Email cannot be delivered
It, however, properly reflects the options as I change them in the config.
DEBUG o.s.m.internal.util.SessionLogger - starting async mail with session (host: smtp.<REDACTED>.com, port: 587, username: <REDACTED>, authenticate: true, transport: SMTP)
DEBUG o.s.m.internal.util.SessionLogger - starting async mail with session (host: smtp.<REDACTED>.com, port: 587, username: <REDACTED>, authenticate: true, transport: SMTPS)
DEBUG o.s.m.internal.util.SessionLogger - starting async mail with session (host: smtp.<REDACTED>.com, port: 587, username: <REDACTED>, authenticate: true, transport: SMTP_TLS)