Hi    I am trying to set up a PutEmail processor for my Outlook email id.   I have configured it as shown in the image below.     When I try to send an email , it is giving an error. I have given the error log below.   2021-08-13 18:32:15,646 INFO [Flow Service Tasks Thread-1] o.a.nifi.controller.StandardFlowService Saved flow controller org.apache.nifi.controller.FlowController@7d98c7ba // Another save pending = false 2021-08-13 18:32:20,809 ERROR [Timer-Driven Process Thread-9] o.a.nifi.processors.standard.PutEmail PutEmail[id=b60e7770-0178-1000-4506-3989ba9583a9] Failed to send email for StandardFlowFileRecord[uuid=cb854007-dbe3-4917-9c13-786a65cec122,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1628858727173-1, container=default, section=1], offset=87505, length=21],offset=0,name=cb854007-dbe3-4917-9c13-786a65cec122,size=21]: 451 5.7.3 STARTTLS is required to send mail [BM1PR0101CA0024.INDPRD01.PROD.OUTLOOK.COM] ; routing to failure: com.sun.mail.smtp.SMTPSendFailedException: 451 5.7.3 STARTTLS is required to send mail [BM1PR0101CA0024.INDPRD01.PROD.OUTLOOK.COM] com.sun.mail.smtp.SMTPSendFailedException: 451 5.7.3 STARTTLS is required to send mail [BM1PR0101CA0024.INDPRD01.PROD.OUTLOOK.COM] at com.sun.mail.smtp.SMTPTransport.issueSendCommand(SMTPTransport.java:2108) at com.sun.mail.smtp.SMTPTransport.mailFrom(SMTPTransport.java:1609) at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1117) at javax.mail.Transport.send0(Transport.java:195) at javax.mail.Transport.send(Transport.java:124) at org.apache.nifi.processors.standard.PutEmail.send(PutEmail.java:541) at org.apache.nifi.processors.standard.PutEmail.onTrigger(PutEmail.java:395) at org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27) at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1174) at org.apache.nifi.controller.tasks.ConnectableTask.invoke(ConnectableTask.java:213) at org.apache.nifi.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:117) at org.apache.nifi.engine.FlowEngine$2.run(FlowEngine.java:110) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) 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) 2021-08-13 18:32:29,605 INFO [pool-12-thread-1] o.a.n.c.r.WriteAheadFlowFileRepository Initiating checkpoint of FlowFile Repository 2021-08-13 18:32:29,615 INFO [pool-12-thread-1] o.a.n.wali.SequentialAccessWriteAheadLog Checkpointed Write-Ahead Log with 22 Records and 0 Swap Files in 9 milliseconds (Stop-the-world time = 5 milliseconds), max Transaction ID 53498 2021-08-13 18:32:29,615 INFO [pool-12-thread-1] o.a.n.c.r.WriteAheadFlowFileRepository Successfully checkpointed FlowFile Repository with 22 records in 9 milliseconds 2021-08-13 18:32:30,049 INFO [NiFi Web Server-99] o.a.n.c.s.StandardProcessScheduler Stopping PutEmail[id=b60e7770-0178-1000-4506-3989ba9583a9] 2021-08-13 18:32:30,050 INFO [NiFi Web Server-99] o.a.n.controller.StandardProcessorNode Stopping processor: PutEmail[id=b60e7770-0178-1000-4506-3989ba9583a9] 2021-08-13 18:32:30,050 INFO [Timer-Driven Process Thread-10] o.a.n.c.s.TimerDrivenSchedulingAgent Stopped scheduling PutEmail[id=b60e7770-0178-1000-4506-3989ba9583a9] to run     Previously, I have used my outlook email with PutEmail and it worked fine. Now I trying with newly created outlook email id and I am getting above error.   How should I fixed this error? Do I need to update something in the email setting? Please guide me , Thanks  ... View more