Make mail.webplatformstaging.org to be a "non exit" SMTP blackhole.

[renoirb]

Follow up on team-webplatform-systems mailing list message.

Tasks

• Do not forward system messages such as bounces and notifications to mailing list, keep them locally we’ll Configure system emails to be saved on mail node, make logstash read through IMAP plugin #127
• Configure it to read mail from the terminal or from a web based Maildir viewer (e.g. mutt)
• Same configuration as production (i.e. other VMs sends mail to mail.webplatformstaging.org)
• Document how to maintain
• For staging:
  • Configure Postfix to not send mail outside
  • make it catch-all

[renoirb]

Worked 4h.

• Catch all system mail, local mail client mutt
• Documentation started at https://docs.webplatform.org/wiki/WPD:Infrastructure/procedures/Maintaining_email_services
• In staging, do not relay emails to popular email providers (not catch "ALL" yet)

[renoirb]

Worked 1d, will do the job on staging. So far, the feature will only be used from staging environment and superseedes relay=smtp to use relay=lurker, so no appending into /var/mail/username, but rather directly added to the lurker database.

We don’t want to archive those emails anyway.