Jhipster Health Endpoint fails when mailserver not connected - spring-boot

Question

JHipster / Spring boot provides a nice endpoint /management/health, where it aggregates health information for subsystems like db, disk, and mail.
Unfortunately, when the connection to the mail server fails, the whole endpoint fails. So you do not get information what has failed.
I get a strack trace like this:
o.s.b.a.health.MailHealthIndicator : Health check failed
com.sun.mail.util.MailConnectException: Couldn't connect to host, port: XXXX, NNNN25025; timeout -1
...
at org.springframework.boot.actuate.health.MailHealthIndicator.doHealthCheck(MailHealthIndicator.java:40)
at org.springframework.boot.actuate.health.AbstractHealthIndicator.health(AbstractHealthIndicator.java:43)
at org.springframework.boot.actuate.health.CompositeHealthIndicator.health(CompositeHealthIndicator.java:68)
at org.springframework.boot.actuate.endpoint.HealthEndpoint.invoke(HealthEndpoint.java:85)
at org.springframework.boot.actuate.endpoint.mvc.HealthMvcEndpoint.getCurrentHealth(HealthMvcEndpoint.java:177)
at org.springframework.boot.actuate.endpoint.mvc.HealthMvcEndpoint.getHealth(HealthMvcEndpoint.java:166)
at org.springframework.boot.actuate.endpoint.mvc.HealthMvcEndpoint.invoke(HealthMvcEndpoint.java:143)
This is spring boot 1.5.9
Where should I fix this, so that the exception is catched and instead a an error status is returned?

Answer 1

You have to turn on your SMTP server or disable checks to it.
To disable checks to SMTP server:
management.health.mail.enabled=false
To disable checks to all server:
management.health.defaults.enabled=false
for more information, see http://www.briansjavablog.com/2017/09/health-checks-metric-s-more-with-spring.html
I believe you can handle this error with the ExceptionHandler for 1.5.9 version of Spring Boot since the newer version there is no such problem:
#ControllerAdvice
public class ExceptionController {
#ExceptionHandler(MailConnectException.class)
public ResponseEntity<?> mailExceptionHandler(MailConnectException e) {
// Do your treatment ...
} ...
}