Simple steps to verify email id existence

Email id exists or notOur team always face email existence problem when they try to:

  • Verify the  registered account holder’s email id or
  • While sending mail to anonymous user who posted comment with some fake email id or
  • To check, if that email address is still valid (ex: 2 years back emailed was valid but not now)

Well it’s not possible to know 100% whether given e-mail address exists in real or not but it will be handy in majority of the cases. You can do it manually also if you are in Linux box using host or nslookup and telnet command. I would prefer host command for this purpose.

How it works:

  • Check if domain name exists or not using ping command
  • If domain name exists then check if it has any mail handlers i.e. mx records in DNS. Use host or nslookup command for it
  • If mx record exists for that domain name use that mail handler using telnet command
  • Use telnet and smtp command to verify user email id. If you get 250/Ok for user email id. You may assume that it exists.

Here many things came into the picture while testing various mail ids from various mail handlers. I will discuss it under “possible ways of failures”

Steps to check the email existence manually

1.       Get the mail id to verify (we can get domain-name from this format to use it in our next step userid@domain-name . For

2.       Either use nslookup command or host command to get mail server address (Lists of mx records from DNS)

a.       Using nslookup:
nslookup –type=mx domain-name

b.      Using host :
host –t mx domain-name

3.       Get the least digital value’s mx record to use it in telnet

a.       telnet mxrecord port-no i.e. telnet 25

b.      Once connected use SMTP commands to know if email id exists or not. It will return 250 as a return code with OK or Accepted. Depending upon mail server configuration and Linux flavors too.

Let’s see it practically with all combination of commands, inputs and outputs 😀

Output from nslookup (it will show many more things which I have not shown here)

$ nslookup -type=mx
Non-authoritative answer:       mail exchanger = 20       mail exchanger = 30       mail exchanger = 40       mail exchanger = 5       mail exchanger = 10

Output from host command ( I prefer this over nslookup )

$ host -t mx mail is handled by 30 mail is handled by 40 mail is handled by 5 mail is handled by 10 mail is handled by 20

Get the value which has lowest ranked digit. In this case it is 5 so take for our purpose
Either use host or nslookup for the first stage.

Telnet outputs:

Step 1

telnet 25
Connected to
Escape character is '^]'.
220 ESMTP hk4si16050652obc.168

Step 2 (type helo, if it didn’t work try helo hi, if it didn’t work too try ehlo then )

250 at your service

Step 3 (type any valid email id. Invalid email id will say ok but after rcpt to it will throw an error and don’t skip this step)

mail from: <>
250 2.1.0 OK hk4si16050652obc.168

Step 4 (You need to provide email which needs to be verified.  Ok means it may exists. Not 1005 guaranteed on existence but we can infer that this email id may work)

rcpt to: <>
250 2.1.5 OK hk4si16050652obc.168

Telnet outputs on failure (Various reasons are there)

1.       Network is unreachable. (sometimes it is reachable form one host but not from others)

telnet 25

telnet: connect to address Connection timed out
Trying 2001:4860:8005::1b…

telnet: connect to address 2001:4860:8005::1b: Network is unreachable

telnet: Unable to connect to remote host: Network is unreachable

2.       Error at mail from:<mail-id> :

  • Don’t forget to use <> while typing email id. is wrong. is correct
  • Never use space before or  after mail id
  • Don’t use single quote or double quote while typing email id

3.       If email id exists but it doesn’t show up 250/ok then below reasons may justify this:

  • Server response delayed
  • Email address black listed
  • Email does not exist  (even if it existed 2 years back )

Steps to check email existence using Perl

  1. Get Mail::CheckUser module from CPAN
  2. Install it either manually or using cpan command
  3. Write simple script using this module and check the output

Good thing with this script is:

  • You don’t need to use any command like host, nslookup telnet and don’t need to remember all those SMTP commands.
  • Just pass the email id rest thing it will do.
  • Internally it checks:
  • It checks the syntax of an email address.   
  • It checks if there any MX records or A records for the domain part of the email address.
  • It tries to connect to an email server directly via SMTP to check if mailbox is valid. It can detect bad mailboxes in many cases.

Here is the fully working Perl script

Why still this trick doesn’t assure 100% proof that email id exists or not?

There can be many reasons for not trusting on this script or the above said manual steps. Best way is to send an email to the given email id. If it bounced back, means it doesn’t exist or can’t be delivered. (I chat with a person in gtalk but can’t send an email to that person. Strange isn’t it).

  • There may be server delay
  • Email id may be black listed
  • It may say it exists if it has to bypass proxies
  • Final output will depend upon server settings which may be using  an algorithm to stop spammer like stuffs
  • For instance SMTP defines the VRFY command for this purpose but gmail doesn’t support it.
  • Never send bulk emails, your mail id will be flagged as a spammers by many hosting companies
  • You may not get proper result because network is unreachable or down by that time

Note: This was just for educational purpose and found helpful for web masters or admins. Don’t use it as spam stuffs, you IP address and your mail id will be blacklisted. Like has been blacklisted from various mail servers.

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RPM package manager for beginners

RPM Linux logoRPM is a powerful software manager for Linux. Earlier it was meant only for Redhat but now it is used in all the Distro which uses rpm for managing their software. 

//There are actually two types of Distro. One is RPM based and other is Debian based. Distro which uses .rpm software is called rpm based linux example: Redhat, fedora, centos etc  and  distro which uses .deb software is called debian based linux example: Ubuntu, Debian, Knoppix etc. This is simillar to Windows system. In windows .exe is used whereas in linux .rpm and .deb is used.//

RPM can install, remove, query and validate the software in the system. There are some good graphical programs which install rpm software but first i will tell you about command line method.

Querying the System

How to look which all software are installed in the system. Here is the command for it:

rpm -qa | more

Let me explain you this. Here rpm  tells the system that you are going to run rpm program. -q tells the sytem about Query operation. a in -qa is for listing all the software. |more is not the feature of rpm but is linux command which tells the system to list the output one page at a time.

How to get info for the single software. Here is the command for it:

rpm -qi vlc

Here i option require the specific package name. So specific package name is given, i.e vlc.

Installing Software in the System

rpm -ivh vlc.rpm

Here vlc.rpm is not the full package name, it is just an example. i is for install, v is for verbose message in case installation fails and h option show the progress mark with hash.

If  you want to update package the use U instead  of i i.e rpm -uvh vlc.rpm.

Removing Software

    rpm -e vlc

e option is used for erasing. But sometimes this will not work due to some dependency. vlc many be dependent on some othe package. so in this case -nodeps option is used. and the command is:

    rpm -e –nodeps vlc

Sometimes packages are not removed properly. For example, if you try to install software and the rpm says that it is alreay installed, and then when you try to remove it then rpm says it is not installed. In this case -force will help to remove this problem. Here is the command for it:

rpm -ivh –force vlc.rpm

Regarding Graphical installer of RPM

People who are working on Linux generally don't use graphical installer. For beginners i think they can have feel of it but i wont recommend this.

There is a software called GnoRPM. To start GnoRPM type gnorpm in the command line.

GnoRPM software


If you have any query related to package manager then just post your query here. There are some other good command line way to install software from internet without worrying about dependency, which will be posted as new topic. Just keep following us.



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Root password lost – recover it here!

Need to login on to LINUX machine – but don’t have the privilege? – or want to gain root privilege?
Pre Requisite – you need the access physical or command line or console access to reboot the machine.

Follow the steps :-

  1. The very first screen when you restart the linux machine – press an enter or space whichever works and this will take you to the snapshot of step 2.

Kernel menu

                                                                                Fig 1

  1. You will get this screen –


                                                                                Fig 2

Press Enter. You will get the screen in Fig.3

Kernel console

                                                                                Fig 3

Press e in the end of 2nd line , the one starting with kernel, to enter the edit mode.

  1. You will get the screen in fig 4, add “s” at the end to login next time in single user mode Type Enter

single user mode

4. After the step 3 you will get this screen, press b to reboot.

After single user edit

  1. After the reboot, below is the screen you will get-

After Reboot

Now you can change the password by typing passwd,it won’t ask you this time for the old password.

password change

Now, you have successfully changed the root password.

PS : Remove thes “, that you have put in there previously by using the same procedure. And next time you reboot you can login as root!!

Any query/help/suggestion/feedback regarding this is welcome. Please feel free 🙂 

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How to use multiple files efficiently in vim editor

Many time we need to work with multiple files all together. If its windows system then we can use some GUI based editor to accomplish our task. But what if you are on putty or have only CLI(Command Line Interface) as an option to  edit your files. I prefer using vim editor.

After doing some experiments and knowing some important commands, I though to share with you. So i have written few commands point wise which may be useful for you while editing multiple files using vim (not GVIM, although these commands are valid there too.)

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Basic useful vim commands for everyone

I know it’s not a new topic to discuss and it has lots of online contents already available over the net. But Then I thought it would be useful to this site’s visitors and can have online repository on vim most commonly used commands.
This post has only most commonly used vim commands which we use in our day today development activities. This post will be very helpful for those who wish to learn vim editor from the scratch and it can be useful for all other vim users too.

So, first open the file by using vim filename (single file at one time). I will be posting very soon about manipulation on multiple files using vim editor.

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Reset any password in windows through windows key enterprise

Windows Key EnterpriseHave you ever imagined, what will happen, if you would forget or compromised your login password in Windows O.S.?
There may be a situation when your friends or relatives may play prank with you and will change administrator password. What you will do then?

In short, if you are using Windows Operating Systems and want to get rid of forgotten/lost password or want to reset almost all the existing password at one go. Then “Windows Key Enterprise Edition is for you only.”

Here are the listed features of this particular software:
Just burn it into CD and you are done!


  • 100% recovery rate
  • All passwords are reset instantly
  • Windows 7 New!, Vista, Vista SP1 supported
  • All Windows Workstations supported
  • All Windows Servers supported, including Server 2008 (Windows Key Professional and Enterprise editions only) New!
  • Resets passwords with a bootable CD-ROM
  • Resets passwords with a bootable USB drive (Windows Key Professional and Enterprise editions only)
  • Burns password reset CD
  • Resets local Administrator passwords
  • Resets Domain Administrator passwords (Windows Key Enterprise edition only)
  • Resets local policy settings
  • Resets secure boot options: startup password or startup key disk
  • Displays account properties
  • Supports all Service Packs
  • Supports RAID/SCSI/SATA drives Updated!

Its latest version is: 10.3.2585 whose archived size is: 5.12 MB (8.2 MB approx in iso format). It’s a shareware software. So you need to pay to use its full version. You can try demo though.

Other versions are Windows Key Professional and Windows Key only which has limited features.
Features of Windows Key Enterprise

Image Source:

Download its Torrent file form here


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4 simple steps to use fonts other than English in MS word

[caption id="" align="alignleft" width="155"]Windows Custom font Windows Custom font[/caption]

Most of the internet or computer users use Microsoft Office word for document purpose (Those who use Microsoft Operating Systems). This blog will show you how to use different text fonts other than English text.
For example: How to use Hindi , Punjabi, Bengali, Tamil, Malayalam fonts in MS word.

Follow these steps to install your desired fonts:

  1. Download the fonts that you wish to use in MS word. Foe ex: Hindi, Marathi, Bengali, Punjabi, Tamil, Malayalam etc.   It should have .tff extension. Ex: hindi_font.tff
  2. Save this font anywhere in your system and then copy it to fonts directory. You can reach to Fonts directory in 2 ways
    1. Open C:/Windows/Fonts (will work in Any Windows O.S. like XP, Vista, Win7 etc)
    2. Got to Control panel there you will see Fonts Directory in Windows XP and Control Panel\Appearance and Personalization\Fonts for Windows Vista users
  3. Open that Fonts Directory and just paste the fonts. You are Done!
  4. Now open MS word and you will see that font name or font style in your font field.

I have tested it on Windows XP and Windows Vista only. If you find any issues in installing fonts into your system or  facing problem in using it. Please let us know we may solve your issues.

You can download few common fonts that may be useful for you from the attached links shown below:

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How to change the default location of My Documents

In Windows O.S. My Documents resides at C:\Documents and Settings\username by default and whatever you download would go there by default. Ex: gtalk shared files, gmail documents, songs , pictures etc (unless and until you have not specified the alternate path for downloads).
Nobody wants to go deep inside to open a file. At least I never choose my documents for my downloaded stuffs storage purpose.

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