Translations:Complete Virtual Mail Server/Postfix additions/45/en

Hackers, spammers and everybody else can obtain information from the mail server by using the HELO and EHLO commands. Spammers usually put fake information in the HELO greeting and thus restricting and rejecting connections from servers that do not properly identify themselves can only be good. Postfix offers the  variable to tune how to respond to connections. Restrictions here have to be thought over carefully however. Locking down the server too tight may make it so messages are rejected because the other server is just poorly configured. A quick overview of the available options.