On Wed, Mar 21, 2001 at 12:41:27PM -0500, Gopi Sundaram wrote:
> On Wed, 21 Mar 2001, Peter van Dijk wrote (quoting me):
>
> > > http://www.imap.org/papers/imap.vs.pop.brief.html
> >
> > And what is your *own* opinion? I prefer POP because IMAP makes
> > users leave mail on server, amongst others.
>
> That is one of the reasons why I prefer IMAP. I don't like leaving my
> email lying on the various machines that I check my email from. There
POP does this too, if you choose.
> are several other reasons, but are irrelevent to this discussion,
> which follows:
>
> > Uh. You are confused. Are you providing pop+imap or shell
> > services?
>
> Both. And we have people that run Netscape on the mail server.
> That's what we have. What is *really big* ? One of the aforementioned
> people had a 200MB mbox (which almost constantly crashed Netscape, and
It's not the size of the mailbox so much as the number of mails in the
mailbox. Depending on the file system, anything more than about
2-3,000 mails in a single mailbox will start to slow down a fair
amount.
> made Pine loop forever). I'm guessing that that won't be a problem if
> converted to maildir. I also read Mark Delany's post that dismisses my
> fears of scalability of the maildir format.
The point is that very few Maildirs reach the size where they fail
completely, on some file systems they just get very slow due to the
linear structure of the directory.
Do an experiment: run one of those mbox-to-maildir convert programs
(from www.qmail.org) on your 200MB mailbox - load it into a Maildir
and aim mutt at it and tell us what happens. Tell us how it compares
to pine loading it from mbox. Then delete one of the mails and
exit. Tells us how mutt performs and tell us how pine performs. In
fact do all your normal user interactions on each mailbox type and
share your results with us.
To do this experiment, all you need do is install mutt and download a
perl script. Surely a small price to pay to get some certainty for
yourself.
> Ideally, I would like mail to still be delivered to /var/mail/ in
Why do you want it in /var/mail particularly, apart from the fact that
you're used to it being there? If you're building a box from scratch
that is only a network service, I don't see where this requirement
comes from.
> whatever format, as long as I can get POP/IMAP servers to support it.
> Then users can read their email from NFS mounted spools when on our
> network, and via IMAP from anywhere else.
mbox is woeful across NFS. Try your 200MB mbox on an NFS server for a
while and draw your own conclusions. Remember that each open of an
mbox requires reading the whole mailbox and scanning from "From "
lines - all 200MB of it across the network. Opening a Maildir requires
reading the directory of the Maildir which is typically much smaller.
The idea of NFS mounting Maildir wasn't so that command line people
could get at it, it's so that other network service servers can share
it.
If people are using pine and netscape then can't both of these
programs be configured to acess a POP/IMAP server? In which case they
have no need to see the physical file structure. Once you move them
off the physical file structure onto a network service, you have
*much* greater flexibility.
> I guess if I use the maildir format, setting up redundant mailservers
> becomes easy. Here's my understanding:
>
> * equal priority MX records for two servers.
> * both servers running qmail, mail stored in an NFS mounted spool dir.
> * One or more servers that run IMAP/POP services that people can
> connect to (perhaps through one alias - mail.domain)
>
> Have I got it right?
Indeed.
Regards.
