I've seen an increased number of issues with some domains that use fakemx.net to deny mail and am looking for some advice on how to best reject email for domains that only have one MX record that points to fakemx.net servers.
While I question the effectiveness, I have no problem with someone trying to detect bad mail senders. Unfortunately, my server finds itself trying to do legit business and being "seen" by fakemx.net and having messages back up in my queue and continually retry doesn't make me happy. I'd like to immediately reject mail for all destinations with ONLY a fakemx.net record. While I could block these as I find them, I'd prefer to detect it if possible. One such: hitmail.com mail is handled by 0 mx.fakemx.net. My thought is to use the transports mechanism and BOUNCE the message... I could scrape the logs and update transports with something like: *.example.com error <http://www.postfix.org/error.8.html>:mail not deliverable (only destination is fakemx.net)* but as we know, over time systems get fixed. I'd prefer to do this detection on the fly as part of the delivery attempt. Can someone provide a suggestion on how to best accomplish this? Thanks jon
