not hard to try

How to do it:

1. Go to Start > Run.

2. Type telnet mail.yourserver.com 110. If your POP3 port is different from the default 110, please change accordingly.

 

telnet port 110

3. Telnet would connect to your mailserver at port 110. Once connected, it will show the message +OK Hello there.

4. Now you’ll have to login using the user command. Some pop3 username requires fullemail address as login and some only username.
Type user [email protected]
You will now see the message +OK Password required.

5. Type pass yourpassword
If you’ve entered a correct password for the user, you will get the message +OK logged in.

6. You can now type the command list to list all the messages on the server and their sizes in bytes.
You should see a message that says +OK POP3 clients that break here, they violate STD53.
1 2243
2 2841
3 1241188
4 4932
The above image shows that you have 4 emails on the server, they are listed in order from oldest first to newest last.

7. To view any of the email message, use the retr command followed by the message number that you see in the list command. It will return the whole message including all headers. Example, retr 3.

8. To delete a message, use the dele command followed by the message number. Example, delete 3

9. Type quit to end the session.

Delete email using Telnet

Tip: If you accidentally deleted a wrong email message, quickly type rset. It will resurrect the email message. When you use the dele command, the message is only marked for deletion and will only permanently delete the messages once you quit the session.

 

Ref: http://www.raymond.cc/blog/archives/2008/10/03/manually-delete-pop3-emails-without-accessing-webmail-or-using-email-client/