If you run your own Postfix SMTP server however, there are lots of things you can do to stop spam. This is a little crib sheet of what I do on most of my servers (as much for my ease-of-access as for other people).

Client configuration can be just as big of problem as the set up for the server. One of the problems is that not all clients, both Linux and Windows, are capable of handling TLS or SMTP AUTH. That is getting better but it is still a problem. One great alternative client is Thunderbird, Icedove if you are on Debian.

This tutorial shows how to set up a CentOS 5.x server to offer all services needed by virtual web hosters. These include web hosting, smtp server with (SMTP-AUTH and TLS, SPF, DKIM, Domainkeys), DNS, FTP, MySQL, POP3/IMAP, Firewall, Webalizer for stats.

YPOPs! is an application that provides POP3 and SMTP access to Yahoo! Mail. This application is more like a gateway. It provides a POP3 server interface at o­ne end to talk to email clients and an HTTP client (browser) interface at the other which allows it to talk to Yahoo! The same concept holds good for SMTP as well.It works with all know email clients like Outlook, Thunderbird, Evolution, Eudora etc.

This is a tutorial on how to send mails using Python smtplib through Gmail SMTP.

Although SMTP blocking of e-mail spam is a best practice, many anti-virus products include the dangerous option of blocking when a Received header is on a blacklist. But it is possible for a legitimate, secure system to have its e-mail blocked by this boneheaded technique. Do not use it!

I know this topic is somewhat advanced for some of you, but for others hopefully this will be useful. So what is a load balancer? To better understand the term, let me explain to you a bit the meaning of load balancing.

Global Server Load Balancing is the automatic routing of users to the nearest / fastest server to them based on their source IP. Typically a GSLB solution requires expensive application switches at each site, and additional software licenses that run into the thousands of dollars.

A good way to see how your Web applications and server will behave under high load is by testing them with a simulated load. We tested several free software tools that do such testing to see which work best for what kinds of sites.