Individual Mail Relay

See our bulk mail relay documentation for information about how our bulk and list email is relayed.

See email deliverability - resources for handling devirability issues.

This page describes how email is relayed via, which is used by our individual email clients to send mail.


We have two individual mail relay servers: and

The servers are both for proxying IMAP and POP connections and also provide smtp relay service for authenticated users using postfix and saslauthd.

IP allocation

IPs are allocated via puppet via the gil.pp and paulo.pp puppet files.

When an IP gets blocked or otherwise becomes un-usable, follow these steps:

  • Read both gil.pp and paulo.pp for comments about past abuse reports for IP addresses previously assigned
  • Pick a new IP address and add it both as an A record and PTR record pointing to the host (e.g. or
  • Add it to the .pp file - both using m_interface::set AND also using the smtp_bind_ip argument of m_mailsubmission
  • Commit and push
  • Run ifup <interface> if you added a new interface
  • Test it to ensure it is not ending up in the blocklist of our major providers:
    filter-check --sendvia localhost --sendto yahoo
    filter-check --sendvia localhost --sendto gmail
    filter-check --sendvia localhost --sendto outlook

The new IP will be automatically added to our record once a day - but you can manually make that happen with:

su -l www-data -c 'cd /usr/local/share/red/ui/sbin/ && DNS_LOOKUP_LOGIN="" ./red-spf-generator'
Last modified 3 years ago Last modified on Sep 19, 2017, 12:19:00 PM