[kwlug-disc] Self-hosted email leaks home IP address

[Ron]

Chris Irwin via kwlug-disc wrote on 2026-03-10 13:37:

> Also, does this only act on mail you're sending? Or will mail you're 
> receiving be similarly altered?

For the record, got a solution from Lee @ SLUUG (St Louis Unix (& Linux) 
Users Group), and it's pretty nifty:

Instead of header_checks in main.cf, there's a trick to make it work in 
master.cf:

smtps     inet  n       -       y       -       -       smtpd
   ## Per Lee @ SLUUG:
   -o cleanup_service_name=submission_hide_home_ip
   ...



submission_hide_home_ip unix n - n - 0 cleanup
   -o header_checks=pcre:/etc/postfix/submission_hide_home_ip.pcre


(Duplicate for submission and smtps entries in master.cf.)


Now it only runs on submissions, i.e. authenticated connections from 
Thunderbird, etc.

Normal mail, on port 25, gets ignored.