ruanwenjun opened a new issue #5369: URL: https://github.com/apache/dolphinscheduler/issues/5369
**Describe the bug** When I send an email with attach file, there will be an error in `alert-server`. ```java 23:21:37.649 [pool-7-thread-1] ERROR org.apache.dolphinscheduler.plugin.alert.email.MailSender - Send email to [[email protected]] failed javax.mail.MessagingException: IOException while sending message at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1365) at javax.mail.Transport.send0(Transport.java:255) at javax.mail.Transport.send(Transport.java:124) at org.apache.dolphinscheduler.plugin.alert.email.MailSender.attachContent(MailSender.java:358) at org.apache.dolphinscheduler.plugin.alert.email.MailSender.attachment(MailSender.java:261) at org.apache.dolphinscheduler.plugin.alert.email.MailSender.sendMails(MailSender.java:211) at org.apache.dolphinscheduler.plugin.alert.email.MailSender.sendMails(MailSender.java:147) at org.apache.dolphinscheduler.plugin.alert.email.EmailAlertChannel.process(EmailAlertChannel.java:45) at org.apache.dolphinscheduler.alert.runner.AlertSender.alertResultHandler(AlertSender.java:162) at org.apache.dolphinscheduler.alert.runner.AlertSender.syncHandler(AlertSender.java:126) at org.apache.dolphinscheduler.alert.processor.AlertRequestProcessor.process(AlertRequestProcessor.java:60) at org.apache.dolphinscheduler.remote.handler.NettyServerHandler.lambda$processReceived$0(NettyServerHandler.java:123) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266) at java.util.concurrent.FutureTask.run(FutureTask.java) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused by: javax.activation.UnsupportedDataTypeException: no object DCH for MIME type multipart/mixed; boundary="----=_Part_0_2080677060.1619191291188" at javax.activation.ObjectDataContentHandler.writeTo(DataHandler.java:896) at javax.activation.DataHandler.writeTo(DataHandler.java:317) at javax.mail.internet.MimeBodyPart.writeTo(MimeBodyPart.java:1694) at javax.mail.internet.MimeMessage.writeTo(MimeMessage.java:1913) at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1315) ... 17 common frames omitted ``` After set `Thread.currentThread().setContextClassLoader(getClass().getClassLoader());` this problem can be fixed. I'm not sure if this is a common problem. https://stackoverflow.com/questions/21856211/javax-activation-unsupporteddatatypeexception-no-object-dch-for-mime-type-multi **To Reproduce** 1. Execute a sql task 2. Send email with attachment **Which version of Dolphin Scheduler:** -[1.3.6] -[dev] -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
