Regex to block spoof in Header Checks

[scroome]

Hi,

I have been trying to put together a PCRE format regular expression in the header_checks file to block senders spoofing our domain, but accepting a few addresses hosted by other companies that do spoof our domain to send mail in to our organisation. i.e.

We want to block allow spoofing of our domain @example.com, but allow a couple of exceptions like test1@example.com, and test2@example.com, test3@example.com.

The regex I have managed to write is working but very cumbersome and may be hard to manage in the future.

Could anyone suggest a better way of doing this instead ? we already have an entry in the sender_access file to block mail being spoofed as @exmaple.com but this does not always work and we are see a rise in the amount of address spoofed messages arriving in to the mail routers ?

Many thanks in advance.

 

[bluegroper]

We use a different technique to reject emails spoofing our domain/s. Greylisting.
It is very successful.
On CentOS the package is postgrey.
Simply, many spammers make up random usernames, and typically only make a single attempt to deliver their payloads.
So those emails are never accepted by postfix.
YMMV

 

[ChrisHirst]

Use Spamassassin.

https://wiki.apache.org/spamassassin/IntegratedSpamdInPostfix

https://wiki.apache.org/spamassassin/WritingRules

Chris.

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