May 30, 2008

Mail sending from EC2 using Postfix.

One of the main problem I found in the EC2 is to sending mail to outside world. Some mail servers like YAHOO and HOTMAIL will block all the orphan mails from EC2 as SPAM. So people cannot send mail like CustomerVerification,NewsLetter from EC2 comfortably.So I am hereby stating an alternate method which was experimented by Paul to get out of this problem. This is sending mails using POSTFIX

1.Amazon EC2
2.Customised AMI from FC4


1.Stop Sendmail
#/etc/init.d/sendmail stop
#chkconfig --levels 2345 sendmail off

2.Installing Postfix
#yum -y install postfix

3.Editing the /etc/postfix/
#vi /etc/postfix/

myhostname =
mydomain =
myorigin = $mydomain

smtpd_banner = $myhostname ESMTP $mail_name
biff = no
append_dot_mydomain = no

alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = localdomain, localhost, localhost.localdomain, localhost
mynetworks =
mailbox_size_limit = 0
recipient_delimiter = +

# SECURITY NOTE: Listening on all interfaces. Make sure your firewall is
# configured correctly
inet_interfaces = all

relayhost = []
smtp_connection_cache_destinations =
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = static:YOUR_AUTHSMPT_USER_ID:YOUR_AUTHSMTP_PW
smtp_sasl_security_options = noanonymous

default_destination_concurrency_limit = 4

soft_bounce = yes

4.Save and Exit
5.Start the Postfix
#/etc/init.d/postfix start
6.Check whether master is listening or not
#ps -ef | grep master

Enjoy Mailing from EC2 without trouble

May 29, 2008

How a DNS works - Simple Example

  • A User opens a web browser and tries to connect to The operating system not knowing the IP Address for, asks the ISP's DNS Server for this information.
  • The ISP's DNS Server does not know this information, so it connects to a Root Server to find out what name server, running somewhere in the world, to know the information about
  • The Root Server tells the ISP's DNS Server to contact a particular name server that knows the information about
  • The ISP's DNS Server connects to Google's DNS server and asks for the IP Address for
  • Google's DNS Server responds to the ISP's DNS server with the appropriate IP Address.
  • The ISP's DNS Server tells the User's operating system the IP Address for
  • The operating system tells the Web Browser the IP Address for
  • The web browser connects and starts communication with
Graphical Representation

May 20, 2008

Amazon S3. New definition in Storage

Amazon S3 (Simple Storage Service) is an online storage web service offered by Amazon Web Services. Amazon S3 provides unlimited storage through a simple web services interface. Amazon launched S3, its first publicly-available web service, in the United States in March 2006 and in Europe in November 2007. Amazon charges fees for data stored and for bandwidth used in sending and receiving data. Amazon S3 uses the same scalable storage infrastructure that uses to run its own global e-commerce network.[citation needed Amazon S3 is reported to store more than 10 billion objects as of November 2007.[citation needed] Many small start-ups and enterprise clients use S3 as a web hosting service, image hosting service, back-up system, and more ...

Amazon EC2. New Wave in Webhosting

Amazon Elastic Compute Cloud, also known as "EC2", is a commercial web service which allows paying customers to rent computers to run computer applications on. EC2 allows scalable deployment of applications by providing a web services interface through which customers can request an arbitrary number of Virtual Machines, i.e. server instances, on which they can load any software of their choice. Current users are able to create, launch, and terminate server instances on demand, hence the term "elastic". The Amazon implementation allows server instances to be created in zones that are insulated from correlated failures. EC2 is one of several Web Services provided by under the blanket term Amazon Web Services (AWS).