How to remove duplicates ?

Is there any way /process to remove the duplicates mails in java ranch ?

What do you mean by "mail" - posts? You can delete your own duplicate posts; the moderators will generally also take care of this.

Let's take this to the JavaRanch forum, where site functionality and procedures are discussed.

Without more information you're forcing us to guess, but is it possible you have more than one account with the same email address and both receive emails? If that is the case, you can disable email updates in one of the accounts.