Email undeliverable when Email Account Configured with Exchange's SMTP Server
-Using server smtp.office365.com
-port 587 is configured
-Error in node logs show: com.sun.mail.smtp.SMTPSendFailedException: 530 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM
When connecting to the Exchange endpoint smtp.office365.com, it is required to authenticate with a user that has an Exchange Online mailbox and that the SMTP sender email account is configured to use TLS.
Enabling TLS for your SMTP email account
- Navigate to email account
- Select Connection Security with TLS
Please see Non-delivery reports in Exchange Online (https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/non-delivery-reports-in-exchange-online/non-delivery-reports-in-exchange-online).