No SMTP server defined
When setting up PaperCut’s Email Notifications customers may experience an issue when using some types of Antivirus/Malware software that intercepts SMTP connections.
Error sending email: Failed messages:
com.sun.mail.smtp.SMTPSendFailedException: 550 No SMTP server defined.
Use real server address instead of 127.0.0.1 in your account.
The above error message indicates that the Java backend of PaperCut is refusing to use 127.0.0.1 as a SMTP server. This has previously been caused by the Antivirus software intercepting the SMTP connection and redirecting it locally rather than to the customers specified SMTP server.
Also see: SMTP Troubleshooting