Hi I am facing a weird issue when i try sending emails from keycloak. I try digging the issue and figured out that when keycloak tries to template the email content in HTML formatat. I dont want to use the plain text body content in the email to go, so i removed the text folder itself from the email theme. When i tried with google SMTP, everything works perfectly fine (even HTML content processes and can be sent). *It says exception writing multi part.* Can somebody help me, where is the problem.? Is it my companies SMTP not allowing it or should i prepare the content in a different manner. ? Below is the stack trace. [0m [31m06:29:44,321 ERROR [org.keycloak.services] (default task-110) KC-SERVICES0029: Failed to send email: javax.mail.MessagingException: IOException while sending message; nested exception is: java.io.IOException: Exception writing Multipart at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1290) at org.keycloak.email.DefaultEmailSenderProvider.send(DefaultEmailSenderProvider.java:125) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:191) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:183) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.send(FreeMarkerEmailTemplateProvider.java:156) at org.keycloak.email.freemarker.FreeMarkerEmailTemplateProvider.sendExecuteActions(FreeMarkerEmailTemplateProvider.java:139) at org.keycloak.services.resources.admin.UsersResource.executeActionsEmail(UsersResource.java:855) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:139) at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:295) at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:249) at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:138) at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:107) at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:133) at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:107) at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:133) at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:101) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:395) at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:202) at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56) at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129) at org.keycloak.services.filters.KeycloakSessionServletFilter.doFilter(KeycloakSessionServletFilter.java:90) at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60) at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84) at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62) at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131) at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46) at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64) at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60) at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77) at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50) at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284) at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263) at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81) at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202) at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: java.io.IOException: Exception writing Multipart at com.sun.mail.handlers.multipart_mixed.writeTo(multipart_mixed.java:83) at javax.activation.ObjectDataContentHandler.writeTo(DataHandler.java:897) at javax.activation.DataHandler.writeTo(DataHandler.java:330) at javax.mail.internet.MimeBodyPart.writeTo(MimeBodyPart.java:1645) at javax.mail.internet.MimeMessage.writeTo(MimeMessage.java:1850) at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1241) ... 57 more Caused by: javax.mail.MessagingException: Empty multipart: multipart/alternative; boundary="----=_Part_0_766978197.1478845783718" at javax.mail.internet.MimeMultipart.writeTo(MimeMultipart.java:548) at com.sun.mail.handlers.multipart_mixed.writeTo(multipart_mixed.java:81) ... 62 more Cheers Abhishek