This article gets into the technical details of how to ping email address or ping email addresses. Its target audience assumes an elementary level of computer and networking knowledge.
The tools described in this article are readily available in Microsoft Windows. Equivalents are accessible in most other operating systems.
For people who know the basics of computer networking, PING is an indispensable tool for diagnosing connection issues.
“Email pinging” works in a very similar way to a standard network “ping” in that there’s a starting machine (e.g., your desktop or servers) and an ending machine (e.g., the mail servers) but that’s where the similarities end. Pinging e-mail boxes is different from regular network pinging in almost every way other than two computers are having a conversation.
High-Level Description of the Ping Process
Before we get into an example of how this is done, let’s first describe at a high level the steps required. It will be helpful to utilize an example e-mail address to help step us through the stages. Let’s use the e-mail address below:
not.a.valid.emailaddress.12345qa@gmail.com
This will be our example e-mail address used throughout the rest of this article.
Get the name of the mail server responsible for e-mail address “not.a.valid.emailaddress.12345qa@gmail.com”.
Using a service called DNS, we can easily work out that the mail servers hosting the example e-mail address return the following as list of servers:
For this example, we’ll use the very first server in the list that is “gmail-smtp-in.l.google.com.”
Using a console tool on our server or desktop, we can “connect” to the mail server “gmail-smtp-in.l.google.com.”
Once we’re connected to a mail server, there is a protocol or set sequence of commands that we can use to converse with a mail server. We’ll go into details on the exact commands later in this article.s
From the recorded sequence of responses and commands in step 3 above, we can efficiently work out if an e-mail address is valid or not.
Detailed Example Of The Ping Process
Taking our example e-mail address “not.a.valid.emailaddress.12345qa@gmail.com”, let’s step through another example using some readily available, desktop tools. The tools we’re using here are available in most of the Windows.
See here: http://youtu.be/f3-5Yrfk-h0
See here: http://www.computerhope.com/issues/chdos.htm
Low Level Walk Through Of E-mail Address Ping
In a console, type:
nslookup
set q=mx
gmail.com
Below is the output from the console window:
C:\>nslookup
Default : google-public-dns-a.google.com
Address: 8.8.8.8
> set q=mx
> gmail.com
Servers: google-public-dns-a.google.com
Address: 8.8.8.8
Nonauthoritative answer:
For the sake of this example, we will use server gmail-smtp-in.l.google.com.
Open another similar console window. Using the mail server above, open a connection as below:
telnet gmail-smtp-in.l.google.com
You should receive a reply similar to the following:
220 mx.google.com ESMTP kz3si11217105wjc.38 – gsmtp
We type commands into our telnet session as follows:
Below is the full transcript of a console, telnet session with the Gmail server for our example e-mail address:
220 mxe.google.com ESMTP u8si7354684wiv.18 – gsmtp
HELO this.com
255 mx.google.com at your service
MAIL FROM:<me@this.com>
250 2.2.0 OK u8si7354684wiv.18 – gsmtp
RCPT TO:<not.a.valid.emailaddress.12345qa@gmail.com>
550-5.1.1 The e-mail account that you tried to reach does not exist. Please try
550-5.1.1 double-checking the recipient’s e-mail address for typos or
550-5.1.1 unnecessary spaces. Learn more at
550 5.1.1 https://support.google.com/mail/bin/answer.py?answer=65966 u8si7354684wi
v.18 – gsmtp
quit
221 2.0.0 closing connection u8si7354684wiv.18 – gsmtp
Connection to host is lost.
The whole conversation with the mail server provides the result that “not.a.valid.emailaddress.12345qa@gmail.com” is not a valid e-mail address. See the lines starting with codes 550-1.1.1.
Pinging email addresses is a reasonably straightforward process once you know how it’s done. Nevertheless, don’t be fooled by the simplicity of the example used in this article. E-mail address pinging is rarely so straightforward.
The things that make the mailbox pings technically challenging are the policies put in place by remote mail servers to check spam. In our example above, I purposely used a Gmail address because Google servers have a reasonably relaxed policy on connecting to them and having a “chat.” Most other mail servers have procedures in place that block the connection from “untrusted” computers.
