On Mar 26, 2010, at 17:14, Mark Goodge wrote: > On 26/03/2010 20:54, listadecorreo wrote: >> >> Hello >> >> in the last month I revived a lot of spam from user_non_ex...@mydomain >> to user_ex...@mydomain..... can I block all received externals mails >> from my domain to my domain... > > It's very easy to block mails from fake_u...@domain to real_u...@domain. Just > turn on sender address verification for your own domains. See > http://www.postfix.org/ADDRESS_VERIFICATION_README.html for details on how > it's configured. > > Blocking forged mails from real_u...@domain to real_u...@domain is harder, as > if any of your users use SMTP servers other than your own then it's very hard > to distinguish between that and forgeries.
Mark, I find that using the Zen spamhaus list does a very good job at blocking mail from real_u...@example.com, for my domains example.com. Daniel