smtp localhost port 25 hardcoded in post-build publisher

[ghost]

build will always fail for now till groupon/DotCi#169 is resolved unless smtp setup exits on localhost ...

since docker does not support multi-inheritance, it would be ideal to avoid having to modify the jenkinsci Dockerfile to also include https://hub.docker.com/r/catatnight/postfix.

[ghost]

Code is not respecting Jenkins.instance.getDescriptor("hudson.tasks.Mailer").setSmtpHost("mailman")

I'm now working to fix https://github.com/groupon/DotCi/blob/master/src/main/java/com/groupon/jenkins/notifications/EmailNotifierBase.java to instead use Transport.send(Message msg, Address[] addresses)

[ghost]

84b30ff

mailman:
  image: catatnight/postfix
  environment:
    maildomain: "mail.example.com"
    smtp_user: "user:password"
  ports:
    - "25:25"