[SYSADMIN] Server post-installation TODO

The server post-installation script seems to have run successfully. Remember to
perform the following tasks:

- once when mail system set-up seems stable, in
  config/dotfiles_user_server/getmail/getmailrc, set [options] delete = true

- ensure the following DNS TXT record for @: v=spf1 mx -all

- run (as root) config/bin/setup_opendkim.sh $selector to set up system for DKIM
  key signing, with a second parameter $keyfile if a key already exists; without
  second parameter, this will generate a new key and print the DNS record to add

- run (as root) config/bin/setup_starttls.sh to set up server-side STARTTLS for
  mail; optionally run with paths to 1) a key file and 2) a cert file as
  arguments if those exist to re-use existing ones

- in the screen weechat/bitlbee session (run "screen -dr"), switch to the
  &bitlbee channel, register with a password ("register", "/oper . [password]"),
  and set up Jabber account with password ("account add jabber
  plomlompom@jabber.ccc.de", "/oper . [password]"), then activate it ("account
  on")