Mail : quota or not quota ? and how to ?

[Emmanuel Halbwachs <Emmanuel.Halbwachs@lpn.cnrs.fr>]

Hello everybody,

I am currently setting up a new mailhost for my lab, ~300 accounts.
It is a woody box, with postfix, amavisd-new, spamassassin, clamav,
courier-imap, squirrelmail from sarge. I will use maildir.
NB my users are colleagues, not customers of a free service.


1. Quota or not quota ?

To my mind, the pros :

- some indelicate users won't block some delicate ones

- coercision : users are obliged to do the housework. They can't say
  "just buy some other disks"

and cons :

- If a user goes on holidays and receive a lot of useless mail (spam,
  jokes from friends with giant MS powerpoint attachement) and
  reaches his quota, some useful mail will be bounced as the
  housework cannot be done by this off-line user

- spending endless time to administer quota and discussing with users
  "I am a power user, I need more space than this user", "I am in a
  hurry, don't have time to do housework, but I need to receive
  urgent mail", etc.

I would like to have your opinions/practises.


2. How to implement quota the best way (and the easy way on Debian) ?

I don't know how mail quota is implemented.
Ideally, I would like thoses features :

- a soft and hard limits

- when over the soft limit, user can receive mail but not send

- users are well noticed, whatever the MUA is. A information mail
  seems to me the best way. Perhaps one notice each time the user tries
  to send mail

- when over the hard limit, user can't receive mail, and is noticed


I would like to RTFM on this subject, so if you have links or
advices, they will be welcomed.

--
Emmanuel Halbwachs              Labo. de Photonique et Nanostructures
tel      : (+33)1 69 63 61 34                             CNRS UPR 20
fax      : (+33)1 69 63 60 06       Route de Nozay F 91460 Marcoussis