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3

This email came from outside your server, from the indicated IP address. Postfix is configured to pass it to Amavis for virus scanning, and when that is complete, Amavis passes it back to Postfix for delivery. This is why there are two localhost Received: lines. One is added by Amavis when it processes the message, and the other one when Postfix re-accepts ...


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The check_sender_access option only applies to the "From" address. To filter based on the "To" address, you can do this in one of two ways. If you want to filter on just the "To" address, just change the check_sender_access to check_recipient_access and keep your current hash file. A more extensible way to filter is by headers. Add the following into ...


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Don't waste your time trying to find the source. It will be another victim. The spammer will have a network of compromised machines they are using. The first thing you should do is apply a password policy and force everyone to change their passwords. Make sure that you change the administrator password as well, as that is the most abused account. Next, on ...


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This is probably just https://en.wikipedia.org/wiki/Internet_background_noise , aka automated scripts looking for vulnerabilities of unpatched servers. You might want to setup a WAF like ModSecurity and have it IP-block suspicious requests. Patch your server regularly.


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The record, without evaluating for correct IP addresses and URLs, is valid. The only limit I am aware of for SPF is exceeding the maximum string length of a DNS TXT record, which is 255 characters. RFC 4408 does give some additional guidelines: 3.1.4. Record Size The published SPF record for a given domain name SHOULD remain small enough that ...



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