PROBLEM
I need to block spammers using forged From: headers.
ENVIRONMENT
- On-Premise Server + WebMail Installations: Version 6.0 > Current Version
CAUSE
Some spammers may wish to use your server as a relay, using SMTP Authentication with forged From: headers.
RESOLUTION
You can block them by doing the following steps:
- Open the configure file in your editor
/usr/local/atmail/mailserver/configure
- Find this line:
accept authenticated = *
- ABOVE that line, add the following:
deny condition = ${if match{$sender_address}{$authenticated_id}{0}{1}}
log_message = Email blocked - Possible Spam - Save the changes to the configure file, and restart Exim
killall -HUP exim
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