Manual for Mail Verifier: Command Line

You can verify email addresses manually with the help of the command line. But first off all you need to install Telnet, because it isn’t included in the standart Windows features.

The way of working with the command line:

1. Run the command line: “Start” → “Run” → “cmd” → “OK”

2. Type “telnet server.com 25”, where “server.com” is the your Internet provider SMTP server, “25” is the port number. To find out the SMTP server and port is possible in the post client server. There is a separate SMTP and connection port value for every mail server (post client server).

For example, «alt1.gmail-smtp-in.l.google.com 25» — for Google



Click “Enter” to start the connection throught the specified port.

3. Type «HELO» command. You need to type the HELO value. This command is used to identify the SMTP client for the SMTP server.


Atomic Mail Verifier detects the HELO value automatically. If you don’t use the program, then it’s necessary to find out HELO value by yourself. Type it into the command line like in the screenshot above with correct syntax.

4. Type MAIL FROM: <test@aol.com>, the sender email address. It must be a valid address to get the «250 ok» server response. Otherwise the program won’t go to the next operation (checking recipient address) before succeeding a previous one.

5. Type «RCPT TO:», the recipient email address.


The response to the typed «RCPT TO:» command must be «250 ok». If there is any error in the response, the typed recipient email doesn’t exist.

Only singular servers allows to type several recipient addresses separated by comma. For example: friend1@anotherserver.com, friend_two@someotherserver.org, friend.3three@Someserver.com

6. Type «RSET». This command is used to transaction rollback within the session. In our case — to cancel the mail delivery.

7. Type «QUIT» to finish the session.

This kind of checking email addresses not only much time but knowledge the basic principles of working with command line and it’s spesific.

Such as:

• basic command line options;
• the way of commands running and grouping;
• to change the command line settings;
• to know where to get necessary information about IP-address, HELO value, SMTP server and connection port and so on.

Atomic Mail Verifier gives an opportunity to work with the email addresses. It requestes for all the necessary data itself and specify automatically. Such a feature make the process of verifying addresses very easy and rather fast.