Scam-backscatter Scam-backscatter prevents backscatter (accept and bounce) on mail servers which don't host mailboxes locally.
Download

Scam-backscatter Ranking & Summary

Scam-backscatter Tags

mail server validates mailboxes prevent backscatter Scam-backscatter validates mailboxes

Scam-backscatter Description

Scam-backscatter prevents backscatter (accept and bounce) on mail servers which don't host mailboxes locally. Scam-backscatter prevents backscatter (accept and bounce) on mail servers which don't host mailboxes locally. The project validates mailboxes by verifying the recipient addresses hosted on a different mail server.Backscatter is when a mail server accepts an email with a forged sender address, then generates a bounce (non-delivery receipt) to the sending address. The figure below shows an example where the sender address is forged:1. An email is sent by smtp.example.com with a forged sender address of user1@example.org to user2@example.net. 2. The email is accepted for delivery by smtp.example.net. 3. The email is then forwarded to mailbox.example.net. As there is no user2 mailbox on mailbox.example.net, a bounce message (non-delivery receipt) is generated by mailbox.example.net to notify the sender address (user1@example.org) of the delivery failure. 4. The bounce message is sent to the mail server at smtp.example.org. 5. user1@example.org receives the bounce message.Your mail server can prevent backscatter by validating the recipient email address in step 2.Build1. Extract the scam-backscatter tarball2. Change the current directory to the one where the scam-backscatter source code was extracted.3. If you are using OpenBSD or NetBSD, rename the Makefile.bsd file to Makefile. If you are using FreeBSD, rename the Makefile.freebsd file. If you are using a Linux distribution, rename the Makefile.linux file to MakefileThe Makefile.bsd file can be used for Solaris. 4. Type make and press Enter to compile scam-archiverInstall1. Copy the scam-back file created above to the appropriate location (/usr/local/sbin for example)2. Generate a new sendmail configuration (sendmail.cf) with the following additional settings:INPUT_MAIL_FILTER(`scam-back', `S=unix:/var/spool/scam/scam-back.sock, F=T, T=S:240s;R:240s;E:5m')dnl3. Create a user (scamback for example) which will be used to run the milter4. Create the /var/spool/scam directory5. Verify that the user created in step 3 has read-write access to the /var/spool/scam directory Requirements: · Sendmail What's New in This Release: · An IPv6 address is now supported for the SMTP backend. · A hostname can be resolved to an IPv6 address. · A backoff feature has been added to limit connection attempts when a connection to the backend SMTP server cannot be established.

Scam-backscatter Related Software