--- name: "smtp-refuser" section: "8" platform: "linux" package: "smtp-refuser" version: "1.0.5.0.1" release: "Debian 4.0 (Etch)" platforms: ["linux"] url: "https://new.carta.tech/smtp-refuser" --- # smtp-refuser(8) refuse SMTP receival with an informative explanation ## NAME smtp-refuser - refuse SMTP receival with an informative explanation ## SYNOPSIS **smtp-refuser** \[ *explanation* \[ *argument...* \] \] ## DESCRIPTION **smtp-refuser** is usually used along with [**tcpd**(8)](/tcpd/8.md) or some other TCP security daemon to bounce messages from IP addresses of known spammers. Advantages of **smtp-refuser** over just blocking connections are that the remote SMTP server will not retry, and legitimate e-mail senders will see a polite message telling them why their mail was blocked and who to call to get around the blocking. Upon SMTP commands **DEBU**, **EXPN**, **RCPT**, and **VRFY**, **smtp-refuser** will report a 550 (no such recipient) error, followed by the contents of the file *explanation*. ### smtp-refuser.conf configuration file */etc/smtp-refuser.conf* consists of two lines. First should contain the name of the person who is to be contacted if blocking prevents legitimate mail transfer. The second line should contain the means of contact (i. e. a telephone number, or an e-mail address). All other lines will be ignored. ### Substitutions in the explanation The following character sequences in the *explanation* file will be substituted: - \`$C' Replaced by the first line of *smtp-refuser.conf* (see above). - \`$P' Replaced by the second line of *smtp-refuser.conf* (see above). - \`$1', \`$2', ... \`$9' Replaced by the first, second, etc. command-line *argument* after *explanation*. Substitution can be prevented using backslash (\`\\') characters: the character following a backslash will be displayed literally (the backslash will be discarded). ## FILES */etc/smtp-refuser.conf* ## AUTHORS Bruce Perens \\ Manual page written by Matej Vela \.