How do you verify if a given email address is real or fake?
When we send a test mail to that email address and if your message doesn’t bounce, it is safe to assume that the address is real. But some web domains may have configured a catch-all email address
meaning that messages addressed to a non-existent mailbox will not be
returned to the sender but in most cases, such email messages will
bounce.
Ping an Email Address to Validate
When you send an email to someone, the message goes to an SMTP server
which then looks for the MX (Mail Exchange) records of the email
recipient’s domain.
For instance, when you send an email to
test@gmail.com, the
mail server will try to find the MX records for the gmail.com domain.
If records exist, then next step would be to determine whether that
email username (
test in our example) is present or not.
Using a similar logic, we can verify an email address from the computer without actually sending a test message. Here’s how:
Let say that we want to verify if the address
marshal@gmail.com exists or not?
Step 1. Enable telnet in Windows. Or if you already have the
Putty utility, skip this step.
Step 2. Open the command prompt and type the following command:
nslookup –type=mx gmail.com
This command will extract and list the MX records of a domain as
shown below. Replace gmail.com with the domain of the email address that
you are trying to verify.
gmail.com MX preference=30, exchanger = alt3.gmail-smtp-in.l.google.com
gmail.com MX preference=20, exchanger = alt2.gmail-smtp-in.l.google.com
gmail.com MX preference=5, exchanger = gmail-smtp-in.l.google.com
gmail.com MX preference=10, exchanger = alt1.gmail-smtp-in.l.google.com
gmail.com MX preference=40, exchanger = alt4.gmail-smtp-in.l.google.com
Step 3. As you may have noticed, it is not uncommon
that we have multiple MX records for a domain. Pick any one of the servers
mentioned in the MX records, may be the one with the lowest preference
level number (in our example, gmail-smtp-in.l.google.com), and “pretend”
to send a test message to that server from you computer.
For that, go to command prompt window and type the following commands in the listed sequence:
3a: Connect to the mail server:
telnet gmail-smtp-in.l.google.com 25
3b: Say byebye to the other server
ByeBye
3c: Identify yourself with some fictitious email address
mail from:<vishaji@gmail.com>
3d: Type the recipient’s email address that you are trying to verify:
rcpt to:<marshal@gmail.com>
The server response for ‘rcpt to’ command will give you an idea
whether an email address is valid or not. You’ll get an “OK” if the
address exists else it will show 550 error.