On Mon, 2005-06-06 at 11:22, Bob Brennan wrote: > I've been called in to solve some massive email problems in a company > that has about 30 employees and an external mailserver. They receive > on average about 100 legitimate emails per day and 3000+ spams plus > the usual virus and worm attacks. > > I am of course recommending FC with Sendmail, Procmail, SpamAssasin > and ClamAV on an inhouse mailserver, all of which I've had experience > and spectacular results with. > > Their spam problem, IMHO, comes from the mailserver they currently use > accepting all non-mailbox email into a postmaster@xxxxxxxxxx account > which has a quota of 1000 emails, which then sends over-quota > rejection notices to senders for all @domain.com incoming; effectively > shutting down all incoming email. My theory is that the reject notices > are taken as replies by spambots and encourages even more spam. > Short-term measures include emptying postmaster@ every 10 minutes and > filtering for valid mis-addressed emails, but even with that the > volume of incoming spam seriously slows down the service. > > My question is - long term - is it better to set up the mailserver to > reject all non-mailbox emails to cut down on the incoming processing > load; or to filter and bit-bucket the spam in the hopes that the > volume will decrease over time with no responses to the spam? Or any > other techniques any of you are using for such problems? > > Thanks in advance for opinions/suggestions, > bob You want to implement greylisting on that mail server asap. It will reduce your spam from 3000+ a day down to around 10 a day. Seriously, I did this for a small company and saw results like that instantly. -- Scot L. Harris webid@xxxxxxxxxx "... all the modern inconveniences ..." -- Mark Twain
