m.roth at 5-cent.us wrote: > Mike wrote: >> Simon Billis wrote: > <snip>> >>> I run a few sendmail servers that run MailScanner/Spamassassin/sendmail >>> (current versions) on Centos 5.4 and Centos 4.8 These boxes accept mail >>> for a large number of domains (6000+) scan the mail removing spam and >>> then forward the ham to another server for delivery. I am attempting to >>> stop any backscatter that these servers cause by only accepting mail for >>> specific users at domain or for domains with a catch-all account. >>> >>> running >>> make -C /etc/mail but this has no effect on the sendmail.cf file. My > > Does it not give output? Have you tried adding -d? > <snip> >> Another would be to use MimeDefang as the framework instead of >> mailscanner. It has an option to check recipient addresses via smtp to >> the delivery servers before accepting. You may have to write a snippet >> of perl to get that right for multiple domains (that's a feature...). >> This is less efficient but works in real time against the addresses that >> will be accepted for delivery. > > I would question how "real time" that would be for every email for 6k+ > domains. If a few have a large client base, or are expecting responses > from a mass emailing, it might start to take a *while*, unless you've got > pretty heavy duty equipment and networking. It's the same thing the downstream server is going to have to repeat in just a moment anyway, but this time it doesn't have to do the other steps. If you are close to capacity already it might push you over the edge - and be worth scripting a way to maintain that frontend virtuser table that makes it a near-instant hash lookup for the relay sendmail. But for the relay it will be a win either way to avoid the much heavier load of spam-scanning stuff to invalid recipients and making the downstream servers construct bounces. -- Les Mikesell lesmikesell at gmail.com