General objective: Student will be able to build a reliable and scalable
mailserver cluster capable of serving 100K+ ISP users

Session 1: Overview

(Introduction: intention is to give a cookbook of working examples to build
your own large mail cluster. Get some idea of services they would like)

Objectives: student will be able to
- give basic structure of an E-mail message
- define and distinguish MUA and MTA
- describe how DNS is used in mail delivery
- use telnet to port 25 and port 110 to manually send and retrieve E-mail
- explain purpose of envelope and distinguish from RFC822 headers

- list key approaches to improve scalability
  (separate smtp and pop3 servers; Maildir vs mbox; no linear password
   files; replicate front-ends and storage back-ends; eliminate points of
   failure)
- list other desirable features of a mail server
  (IMAP; webmail; SMTP delivery to client; per-user quotas; no Unix accounts
  per user; individual accounts and whole domains per mailbox; open
  standards and interchangeable parts)
- explain why we are using exim rather than sendmail
- describe the basic exim mail processing mechanism
  (local_domains; routers/directors; spool)
- find their way around exim documentation

Session 2: Exim configuration

Objectives: student will be able to:
- install exim
- configure exim as a basic outgoing SMTP relay
- replace sendmail using /etc/mail/mailer.conf
- restrict relaying to local addresses only, explain why this is important,
  test policy using exim -bh
- read and interpret mailq and exim log files inc. paniclog/frozen messages
- perform queue runs on individual messages and the whole queue
- use exim -C and -bt to try out a configuration file and debug
  delivery problems (modify configuration file for Maildir delivery)
- use configuration file for a good performance SMTP smarthost
  (non-root, tweaked for large-scale installation)
- configure relaying, outbound and backup MX

Session 3: Mailserver performance tuning and monitoring

- Install qmail-pop3d and test it (Unix accounts)
- FreeBSD: configure maxusers 512, softupdates, ccd striping
- run exim as non-root
- install postal and use it to generate bulk SMTP deliveries
- test pop3 performance using rabid
- use existats, exicyclog and eximon (and df, uptime, ...)

Session 4: Database driven operation; virtual domains

- explain what is meant by 'virtual domains'
- explain why it is desirable not to have accounts in /etc/passwd
- assign hashed directories, create dbm files for domains and
  mailboxes, and configure exim to use them
- create a 'whole domain' mailbox and a single-user mailbox

Session 5: POP3 and IMAP configuration

- create a userdb for courier
  http://courier.sourceforge.net/userdb.html
- install courier-imap (with 'deliverquota')
- start pop3 and imap daemons, deliver and retrieve mail

[as time allows: sqwebmail]

Session 6: Clustering technologies

- describe scaling using round-robin DNS/multiple MX records and layer 4
  switching
- mount NFS backend(s), configure mail to be distributed across multiple
  backends
- configure exim as a database-driven SMTP frontend
- install and use a database-driven POP3 proxy
  http://perdition.sourceforge.net/   and/or
  http://www.i2pi.com/smunge/
- be able to distribute database using rsync, demonstrate awareness of LDAP
  and SQL

(practical exercise will end up with the whole class as a huge mailserver
cluster :-)

Other topics which might be discussed
-------------------------------------
SMTP end-user delivery, ETRN
SMTP authentication
RBL policy controls