Hello,
I am planning to install Linux on my laptop. I will be using it for mailing testing as well as scripting. Basically I want to hand on with Linux to be used as File and Mail Server.
Please advise suitable Linux distribution.
You posted on the Red Hat subforum. You could do this with Red Hat Enterprise or CentOS, but I'm a SUSE guy. OpenSUSE could do all those things, but so could nearly any distribution. You will be best served by looking at, and trying as many as you think you can stand.
How new is the laptop? Laptops are as finicky as the PC platform gets.
Redhat's default mail server combination is sendmail or postfix and dovecot.