Re: [cobalt-users] Evaluating Cobalt RaQ for more than 25000 e-mail accounts

["Steve Werby" <steve-lists@xxxxxxxxxxxx>]

"Jim Scott" <cobaltlist@xxxxxxxxxxxx> wrote:
> 25k? That would take more than one server I would imagine. My Suggestion
> would be to look at a cluster of servers. Would not want to have that many
> accounts on one server.

I have no experience with numbers like that on a RaQ, but the load on the
server will depend on which email protocol is used and what kind of
sustained peak usage is expected.  And I assume this will be a dedicated
email server, otherwise you need to provide *a lot* more detail.  POP uses
less CPU than IMAP so you may prefer a POP-based webmail program
(database-driven may be even better) even though IMAP-based webmail programs
are usually more feature-rich.  Authentication using pam may be sluggish
with that many system users.  You might want to investigate authenticating
against a database like MySQL.  And you'll likely gain huge performance
benefits by maxing out the RAM.  The more CPU the better, but RAM will get
you more bang for the buck IMO.  For an operation planning to support 25k
POP/webmail users I'd suggest researching a vanilla Linux server (more bang
for the buck, configure with specs to meet your needs and optimize software
to run as dedicated email server) unless you really need the GUI of a RaQ or
that's what you happen to have and the decision has been made.

> If you gave each person 10MB of space that would be 250 Gigs of space. Are
> you planning on using external storage?

Good point.  But also keep in mind if your package has a 10MB cap that the
average storage used at any given point across the entire 25,000 user base
will be just a fraction of the cap and if the POP users are retrieving the
email frequently then there shouldn't be much mail in the average user's
box.  FYI, even if the user sets their email client to leave email on the
server recent qpopper versions can be configured to disallow that.  I feel
pretty comfortable that a server with one or two 30 GB drives can easily
handle 25,000 email users if system and procedural mechanisms are in place
to control the amount of email in a user's box.

HTH,

--
Steve Werby
President, Befriend Internet Services LLC
http://www.befriend.com/