[lug] Large email installation

[Sean Reifschneider]

On Sat, Jan 22, 2005 at 10:58:23AM -0700, Chris Brotherton wrote:
>Can anyone point me to a resource online that describes a really large email
>installation?  I am curious about number of servers, how the servers are
>setup, redundancy, etc.

I presume you're talking about about incoming rather than just sending.
As in, a large ISP.  Well, google is doing something fairly different,
using their Google Filesystem stuff.  You can read about that, but that's
not something you're likely to be able to apply unless you work at google.

Most ISPs will set up a back-end NFS store for the e-mail to be stored on,
possibly using "heartbeat" to make the file-server redundant and
highly-available, since it's the single point of failure.  Then they'll set
up a number of machines running SMTP and POP which deliver mail to and
allow reading mail from this NFS server.  Possibly using LDAP for the user
database, but I'd also consider using RADIUS (if all your mail users are
also dial-up users).

Look at Cyrus "MURDER", "LVS" load-balancing and "POP toaster" on google
for some technologies that are commonly used.

Sean
-- 
 Nothing like a river-boat cruise at 3am to make a person realize how
 great life can be - as long as they have a boat.  -- A. Wyskowski, 2002
Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995.  Qmail, Python, SysAdmin