if i like to setup mail server , infra that sits like mail chimp are using. where should i start ? im using CentOS . i must add another question here ? say i did setup mail server .. how can i make my domain not go to spam ?
There are a number of mail servers that are being used out there (Postfix, qmail, sendmail, etc. See http://en.wikipedia.org/wiki/Comparison_of_mail_servers for a list of them). You want to do some research into the various ones out there and pick the right one for you as their feature sets and complexity will likely play a part in which server is right for you. Postfix seems to be a very popular choice, often coming pre-installed with many distros.
After having chosen one, you need to do some reading on your server of choice. You'll have to learn the various configuration options out there and choose ones that are best suited for your situation.
I found that zimbra Open Source Edition is the best mail server out there. (in my opinion)
It might not be very easy to set up but I can provide a step by step guide for debian/ubuntu servers that I wrote myself...
I would recommend looking into the following applications for Spam/AV filtering
- amivisd-new - Content checker
- ClamAV - Anti Virus
- SpamAssassin - Spam filter
- PostGrey - Policy Server/grey listing of address's (only useful if you are using postfix as your MTA)
There is a tutorial by flurdy on how to setup a mail server under ubuntu which i would recommend reading some of the principles will be the same even though the linux distro is different.
How To in question: http://flurdy.com/docs/postfix/
Other things which you can do to try and prevent spam is setup a DKIM record and SPF