Keycloak fails SMTP test connection #41441

pmfgomes · 2025-07-26T00:42:41Z

I have a Keycloak installation in a VPS inside a docker container. I'm trying to enable the email configuration so I can send emails to users, but every time I try to test the connection I get the message "Error! Failed to send email".
I need some help figuring out what am I doing wrong.

My email config is simple:

  From: <my-email>
  Host: smtp.gmail.com
  Port: 587
  ✅Enable SSL
  ✅Enable StartTLS
  Username: <my-email>
  Password: <google app password>

Keycloak version from logs:
[io.quarkus] (main) Keycloak 26.3.2 on JVM (powered by Quarkus 3.20.2)

Logs:

 2025-07-26T00:36:26.092528783Z DEBUG: Jakarta Mail version 2.1.1
2025-07-26T00:36:26.094227882Z DEBUG: URL jar:file:/opt/keycloak/lib/lib/main/org.eclipse.angus.angus-mail-2.0.3.jar!/META-INF/javamail.providers
2025-07-26T00:36:26.094523461Z DEBUG: successfully loaded resource: jar:file:/opt/keycloak/lib/lib/main/org.eclipse.angus.angus-mail-2.0.3.jar!/META-INF/javamail.providers
2025-07-26T00:36:26.095487797Z DEBUG: successfully loaded resource: /META-INF/javamail.default.providers
2025-07-26T00:36:26.096184564Z DEBUG: Tables of loaded providers
2025-07-26T00:36:26.096335241Z DEBUG: Providers Listed By Class Name: {org.eclipse.angus.mail.imap.IMAPStore=jakarta.mail.Provider[STORE,imap,org.eclipse.angus.mail.imap.IMAPStore,Oracle], org.eclipse.angus.mail.smtp.SMTPTransport=jakarta.mail.Provider[TRANSPORT,smtp,org.eclipse.angus.mail.smtp.SMTPTransport,Oracle], org.eclipse.angus.mail.pop3.POP3Store=jakarta.mail.Provider[STORE,pop3,org.eclipse.angus.mail.pop3.POP3Store,Oracle], org.eclipse.angus.mail.pop3.POP3SSLStore=jakarta.mail.Provider[STORE,pop3s,org.eclipse.angus.mail.pop3.POP3SSLStore,Oracle], org.eclipse.angus.mail.smtp.SMTPSSLTransport=jakarta.mail.Provider[TRANSPORT,smtps,org.eclipse.angus.mail.smtp.SMTPSSLTransport,Oracle], org.eclipse.angus.mail.imap.IMAPSSLStore=jakarta.mail.Provider[STORE,imaps,org.eclipse.angus.mail.imap.IMAPSSLStore,Oracle]}
2025-07-26T00:36:26.096535291Z DEBUG: Providers Listed By Protocol: {imap=jakarta.mail.Provider[STORE,imap,org.eclipse.angus.mail.imap.IMAPStore,Oracle], smtp=jakarta.mail.Provider[TRANSPORT,smtp,org.eclipse.angus.mail.smtp.SMTPTransport,Oracle], pop3=jakarta.mail.Provider[STORE,pop3,org.eclipse.angus.mail.pop3.POP3Store,Oracle], imaps=jakarta.mail.Provider[STORE,imaps,org.eclipse.angus.mail.imap.IMAPSSLStore,Oracle], smtps=jakarta.mail.Provider[TRANSPORT,smtps,org.eclipse.angus.mail.smtp.SMTPSSLTransport,Oracle], pop3s=jakarta.mail.Provider[STORE,pop3s,org.eclipse.angus.mail.pop3.POP3SSLStore,Oracle]}
2025-07-26T00:36:26.097317479Z DEBUG: successfully loaded resource: /META-INF/javamail.default.address.map
2025-07-26T00:36:26.098004309Z DEBUG: URL jar:file:/opt/keycloak/lib/lib/main/org.eclipse.angus.angus-mail-2.0.3.jar!/META-INF/javamail.address.map
2025-07-26T00:36:26.098351748Z DEBUG: successfully loaded resource: jar:file:/opt/keycloak/lib/lib/main/org.eclipse.angus.angus-mail-2.0.3.jar!/META-INF/javamail.address.map
2025-07-26T00:36:26.101340946Z DEBUG: getProvider() returning jakarta.mail.Provider[TRANSPORT,smtp,org.eclipse.angus.mail.smtp.SMTPTransport,Oracle]
2025-07-26T00:36:26.103448281Z DEBUG SMTP: useEhlo true, useAuth true
2025-07-26T00:36:26.103482545Z DEBUG SMTP: trying to connect to host "smtp.gmail.com", port 587, isSSL true
2025-07-26T00:36:46.119422818Z 2025-07-26 00:36:46,118 ERROR [org.keycloak.services] (executor-thread-2) KC-SERVICES0029: Failed to send email: org.keycloak.email.EmailException: Password based SMTP connect failed
2025-07-26T00:36:46.119485233Z 	at org.keycloak.email.PasswordAuthEmailAuthenticator.connect(PasswordAuthEmailAuthenticator.java:17)
2025-07-26T00:36:46.119493286Z 	at org.keycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:84)
2025-07-26T00:36:46.119498794Z 	at org.keycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:72)
2025-07-26T00:36:46.119503875Z 	at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:290)
2025-07-26T00:36:46.119508625Z 	at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:284)
2025-07-26T00:36:46.119513045Z 	at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.sendSmtpTestEmail(FreeMarkerEmailTemplateProvider.java:129)
2025-07-26T00:36:46.119534928Z 	at org.keycloak.services.resources.admin.RealmAdminResource.testSMTPConnection(RealmAdminResource.java:1153)
2025-07-26T00:36:46.119539292Z 	at org.keycloak.services.resources.admin.RealmAdminResource$quarkusrestinvoker$testSMTPConnection_978c03204c6731c669c59b7354b55fec7ce5ca91.invoke(Unknown Source)
2025-07-26T00:36:46.119542726Z 	at org.jboss.resteasy.reactive.server.handlers.InvocationHandler.handle(InvocationHandler.java:29)
2025-07-26T00:36:46.119550407Z 	at io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:141)
2025-07-26T00:36:46.119554321Z 	at org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)
2025-07-26T00:36:46.119557508Z 	at io.quarkus.vertx.core.runtime.VertxCoreRecorder$15.runWith(VertxCoreRecorder.java:638)
2025-07-26T00:36:46.119561011Z 	at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2675)
2025-07-26T00:36:46.119564926Z 	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2654)
2025-07-26T00:36:46.119568483Z 	at org.jboss.threads.EnhancedQueueExecutor.runThreadBody(EnhancedQueueExecutor.java:1627)
2025-07-26T00:36:46.119572178Z 	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1594)
2025-07-26T00:36:46.119576176Z 	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:11)
2025-07-26T00:36:46.119581849Z 	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:11)
2025-07-26T00:36:46.119585640Z 	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
2025-07-26T00:36:46.119589052Z 	at java.base/java.lang.Thread.run(Thread.java:1583)
2025-07-26T00:36:46.119592096Z Caused by: org.eclipse.angus.mail.util.MailConnectException: Couldn't connect to host, port: smtp.gmail.com, 587; timeout 10000;
2025-07-26T00:36:46.119595802Z   nested exception is:
2025-07-26T00:36:46.119599075Z 	java.net.SocketTimeoutException: Connect timed out
2025-07-26T00:36:46.119602445Z 	at org.eclipse.angus.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2243)
2025-07-26T00:36:46.119605767Z 	at org.eclipse.angus.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:729)
2025-07-26T00:36:46.119609280Z 	at jakarta.mail.Service.connect(Service.java:342)
2025-07-26T00:36:46.119612747Z 	at jakarta.mail.Service.connect(Service.java:222)
2025-07-26T00:36:46.119615912Z 	at jakarta.mail.Service.connect(Service.java:243)
2025-07-26T00:36:46.119618953Z 	at org.keycloak.email.PasswordAuthEmailAuthenticator.connect(PasswordAuthEmailAuthenticator.java:15)
2025-07-26T00:36:46.119622185Z 	... 19 more
2025-07-26T00:36:46.119625455Z Caused by: java.net.SocketTimeoutException: Connect timed out
2025-07-26T00:36:46.119634968Z 	at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:546)
2025-07-26T00:36:46.119638480Z 	at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:592)
2025-07-26T00:36:46.119641910Z 	at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327)
2025-07-26T00:36:46.119644856Z 	at java.base/java.net.Socket.connect(Socket.java:751)
2025-07-26T00:36:46.119648240Z 	at org.eclipse.angus.mail.util.WriteTimeoutSocket.connect(WriteTimeoutSocket.java:118)
2025-07-26T00:36:46.119651995Z 	at org.eclipse.angus.mail.util.SocketFetcher.createSocket(SocketFetcher.java:366)
2025-07-26T00:36:46.119654971Z 	at org.eclipse.angus.mail.util.SocketFetcher.getSocket(SocketFetcher.java:243)
2025-07-26T00:36:46.119657838Z 	at org.eclipse.angus.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2193)
2025-07-26T00:36:46.119660846Z 	... 24 more
2025-07-26T00:36:46.119663818Z 
2025-07-26T00:36:46.120150952Z 2025-07-26 00:36:46,119 ERROR [org.keycloak.services.resources.admin.RealmAdminResource] (executor-thread-2) Failed to send email 
2025-07-26T00:36:46.120170950Z  org.keycloak.email.EmailException: Password based SMTP connect failed: org.keycloak.email.EmailException: Error when attempting to send the email to the server. More information is available in the server log.
2025-07-26T00:36:46.120174860Z 	at org.keycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:90)
2025-07-26T00:36:46.120178721Z 	at org.ke
8000
ycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:72)
2025-07-26T00:36:46.120182227Z 	at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:290)
2025-07-26T00:36:46.120185886Z 	at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:284)
2025-07-26T00:36:46.120189256Z 	at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.sendSmtpTestEmail(FreeMarkerEmailTemplateProvider.java:129)
2025-07-26T00:36:46.120192612Z 	at org.keycloak.services.resources.admin.RealmAdminResource.testSMTPConnection(RealmAdminResource.java:1153)
2025-07-26T00:36:46.120194814Z 	at org.keycloak.services.resources.admin.RealmAdminResource$quarkusrestinvoker$testSMTPConnection_978c03204c6731c669c59b7354b55fec7ce5ca91.invoke(Unknown Source)
2025-07-26T00:36:46.120197621Z 	at org.jboss.resteasy.reactive.server.handlers.InvocationHandler.handle(InvocationHandler.java:29)
2025-07-26T00:36:46.120199839Z 	at io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:141)
2025-07-26T00:36:46.120202282Z 	at org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)
2025-07-26T00:36:46.120204642Z 	at io.quarkus.vertx.core.runtime.VertxCoreRecorder$15.runWith(VertxCoreRecorder.java:638)
2025-07-26T00:36:46.120206799Z 	at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2675)
2025-07-26T00:36:46.120221469Z 	at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2654)
2025-07-26T00:36:46.120223785Z 	at org.jboss.threads.EnhancedQueueExecutor.runThreadBody(EnhancedQueueExecutor.java:1627)
2025-07-26T00:36:46.120226028Z 	at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1594)
2025-07-26T00:36:46.120228186Z 	at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:11)
2025-07-26T00:36:46.120231537Z 	at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:11)
2025-07-26T00:36:46.120233701Z 	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
2025-07-26T00:36:46.120235875Z 	at java.base/java.lang.Thread.run(Thread.java:1583)
2025-07-26T00:36:46.120237931Z Caused by: org.keycloak.email.EmailException: Password based SMTP connect failed
2025-07-26T00:36:46.120240041Z 	at org.keycloak.email.PasswordAuthEmailAuthenticator.connect(PasswordAuthEmailAuthenticator.java:17)
2025-07-26T00:36:46.120242210Z 	at org.keycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:84)
2025-07-26T00:36:46.120244391Z 	... 18 more
2025-07-26T00:36:46.120246413Z Caused by: org.eclipse.angus.mail.util.MailConnectException: Couldn't connect to host, port: smtp.gmail.com, 587; timeout 10000;
2025-07-26T00:36:46.120248945Z   nested exception is:
2025-07-26T00:36:46.120250950Z 	java.net.SocketTimeoutException: Connect timed out
2025-07-26T00:36:46.120253010Z 	at org.eclipse.angus.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2243)
2025-07-26T00:36:46.120255094Z 	at org.eclipse.angus.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:729)
2025-07-26T00:36:46.120257197Z 	at jakarta.mail.Service.connect(Service.java:342)
2025-07-26T00:36:46.120259266Z 	at jakarta.mail.Service.connect(Service.java:222)
2025-07-26T00:36:46.120261286Z 	at jakarta.mail.Service.connect(Service.java:243)
2025-07-26T00:36:46.120263332Z 	at org.keycloak.email.PasswordAuthEmailAuthenticator.connect(PasswordAuthEmailAuthenticator.java:15)
2025-07-26T00:36:46.120265474Z 	... 19 more
2025-07-26T00:36:46.120267441Z Caused by: java.net.SocketTimeoutException: Connect timed out
2025-07-26T00:36:46.120269572Z 	at java.base/sun.nio.ch.NioSocketImpl.timedFinishConnect(NioSocketImpl.java:546)
2025-07-26T00:36:46.120271634Z 	at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:592)
2025-07-26T00:36:46.120273683Z 	at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327)
2025-07-26T00:36:46.120275785Z 	at java.base/java.net.Socket.connect(Socket.java:751)
2025-07-26T00:36:46.120284010Z 	at org.eclipse.angus.mail.util.WriteTimeoutSocket.connect(WriteTimeoutSocket.java:118)
2025-07-26T00:36:46.120287357Z 	at org.eclipse.angus.mail.util.SocketFetcher.createSocket(SocketFetcher.java:366)
2025-07-26T00:36:46.120294259Z 	at org.eclipse.angus.mail.util.SocketFetcher.getSocket(SocketFetcher.java:243)
2025-07-26T00:36:46.120296560Z 	at org.eclipse.angus.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:2193)
2025-07-26T00:36:46.120325859Z 	... 24 more
2025-07-26T00:36:46.120329714Z

Answered by pmfgomes

Jul 26, 2025

I figure out the problem. The problem is that i'm hosting my VPS in Digital Ocean and apparently they are blocking every smtp port for gmail and that is why this service is not working.

View full answer

pmfgomes · 2025-07-26T13:02:58Z

pmfgomes
Jul 26, 2025
Author

I figure out the problem. The problem is that i'm hosting my VPS in Digital Ocean and apparently they are blocking every smtp port for gmail and that is why this service is not working.

0 replies

Navigation Menu

Repository navigation

Keycloak fails SMTP test connection #41441

Uh oh!

{{title}}

Uh oh!

Uh oh!

{{editor}}'s edit

{{editor}}'s edit

Uh oh!

Replies: 1 comment

Uh oh!

{{title}}

Uh oh!

Select a reply

Uh oh!

Keycloak fails SMTP test connection #41441

Uh oh!

Uh oh!

pmfgomes Jul 26, 2025

Replies: 1 comment

Uh oh!

pmfgomes Jul 26, 2025 Author

pmfgomes
Jul 26, 2025

pmfgomes
Jul 26, 2025
Author