Scott Howard wrote:
As for the primary, how long until it hits the blogs/press/etc that company X's primary mail server has been down for the past 3 months! ("When contacted the company said 'yeah, we know - we like it that way!'")
Thanks for this comment, something to consider. MTAs that are following protocols, from my observations, would appear to not even report the fact that the highest priority MX is unavailable and just deliver straight to the next MX in the chain. So, I am not sure what would lead to people being even aware of the fact unless someone specifically tests the connection as it wouldn't be effecting mail delivery to company X. Further to my posting to this list, I had a number of replies from people on the postfix list. None of them were negative and whilst a couple did point out that they have seen a swing towards Spammers targetting the lowest priority MX only, there is still a lot of spam/virus traffic against the primary MX only and that the technique is worth doing ( for them ). I have now implemented 'nolisting' on all the domains we host, as a trial, and will try to collect some empirical evidence as to whether it is in fact worth doing. It is pretty easy to turn off/on. Whilst I accept that it is not a technique that will even work, appeal or even be considered by some, I am still looking at defense in depth and every technique I can find I will consider. I will post the results in a few weeks time. -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Glen and Rosanne Eustace GodZone Internet Services, a division of AGRE Enterprises Ltd. P.O. Box 8020, Palmerston North, New Zealand 4446. Ph: +64 6 357 8168, Fax +64 6 357 8165, Mob: +64 21 424 015 http://www.godzone.net.nz "A Ministry specialising in providing low-cost Internet Services to NZ Christian Churches, Ministries and Organisations."