Well, about a year ago, I set up a similar system using qmail, and a QMQP load balancing patch that I made which you can get at qmail.org. However, I've since switched to a cluster of postfix boxes behind a load balancing unit. Postfix gives me better performance, I can get better stats from it, it's easier to configure and use, supports ESMTP pipelining (qmail doesn't), has adaptive rate limiting based on how fast the remote server is responding (it will ramp up or back off depending), and generally just makes my life a whole lot easier. I started testing on linux, but I've switched to freebsd because of linux's FD_SET() limitation. I was only able to run about 508 concurrent processes before it would choke. With BSD, I can easily get over 2000 concurrent processes (you need to recompile the kernel with higher NMBCLUSTERS and MAXUSERS and set some sysctl variables). Though, if you have a fast connection, you won't see more than about 700 concurrent processes Right now, I have 5 boxes in the cluster, and the load balancer is set to "least connections" for it's load balancing method. The box which relays mail into it opens 10 threads, so each mailserver gets 2 connections. Make sure you get fast disks, I just stripe my mail spool (not mission critical mail). qmail touches the disk about 3 times more than postfix will, so I highly suggest using postfix, and turn on softupdates or async for your spool (don't use async if you're worried about losing mail in the event of a crash). Now, if this is for a spammer, please forget all that I have just told you. :) Jay > -----Original Message----- > From: Nate Carlson [mailto:natecars at real-time.com] > Sent: Wednesday, January 09, 2002 10:54 AM > To: tclug-list at mn-linux.org > Subject: Re: [TCLUG] High Volume Mail Relay > > > On Wed, 9 Jan 2002, Jay Kline wrote: > > I am doing some research to set up a high volume SMTP relay > server for > > a company. As of right now, they average roughly 4000 7K > messages per > > minute during the work day (a total of about 1 million > messages per 8 > > hour work day). By the end of the year, their estimates are to be > > sending 12 times that. As this is outgoing mail only, > local delivery > > really isnt a big deal, we have one incoming server set up for that, > > and is handling just fine. > > Please tell me these guys aren't spammers? > > -- > Nate Carlson <natecars at real-time.com> | Phone : (952)943-8700 > http://www.real-time.com | Fax : (952)943-8500 > > > _______________________________________________ > Twin Cities Linux Users Group Mailing List - Minneapolis/St. > Paul, Minnesota > http://www.mn-linux.org > tclug-list at mn-linux.org > https://mailman.mn-linux.org/mailman/listinfo/tclug-list >