SMTP - User unknown

Issue

Unable to send emails - SMTPAddressFailedException

Caused by: com.sun.mail.smtp.SMTPSendFailedException: 250 2.0.0 v11L8poI023794 Message accepted for delivery
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <address>... User unknown

Environment

Jenkins LTS

Resolution

Causes:

Invalid email address
Default email address not configured yet nobody@nowhere hasn’t been changed
SMTP server is blocking the mail send somehow

Check Manage Jenkins Configure System - Jenkins Location - System Admin e-mail address

Invalid email address

Confirm that you can send emails manually to this address

Default email address not configured yet nobody@nowhere hasn’t been changed

This is the default when no system email address is set.

An example of an error when this is the issue:

Caused by: com.sun.mail.smtp.SMTPSendFailedException: 250 2.0.0 v11L8poI023794 Message accepted for delivery
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <address>... User unknown
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <not>... User unknown
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <configured>... User unknown
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <yet>... User unknown

at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:1112)
at javax.mail.Transport.send0(Transport.java:195)
at javax.mail.Transport.send(Transport.java:124)
at com.cloudbees.jenkins.plugin.metrics.views.Alerter$EmailRecipient.sendNotification(Alerter.java:2011)
... 5 more
Caused by: com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <address>... User unknown
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <not>... User unknown
;
nested exception is:
com.sun.mail.smtp.SMTPAddressFailedException: 550 5.1.1 <configured>... User unknown
;

SMTP server is blocking the mail send somehow

This can be caused by SMTP administrative settings. Contact your SMTP server administrator.