Tech:Mail

Mail is currently running on misc1 under. The install is a standard postfix and dovecot install with implemented auth controls shared between both. All shell accounts on misc1 automatically become email accounts.

Add new email accounts
Create a new user with a uid between 500-999 with shell set to /sbin/nologin. Example below for john : adduser --shell /sbin/nologin --uid 502 john;

Aliases
Aliases are managed by puppet in the postfix modules (files/aliases).

Anti-spoofing
We use following standard techniques to combat email address spoofing.

DKIM
DKIM is used to sign all emails out-going from misc1. The public key is stored in DNS (in TXT format) and the private key is stored in private git. It can be generated by doing.

This generates a public and private key pair. The private key should be stored in private git while the public key should be added to the DNS repo in order allow the world to verify emails.

SPF
SPF records are set to only accept mails from mw1, mw2, misc1, and Gmail.

DMARC
Our DMARC policy informs to reject If above techniques fails: incoming mail servers are instructed to not accept any mails that does not pass the requirements.