> In this situation, we had to start blocking IP-Ranges to guarantee the
> mailservice. We tried to block only dynamically assigned IP addresses, > to minimize the impact on other users. Unfortunately, this was not > always possible to achieve in the speed of blocking IP Ranges required > to keep our systems alive. Never a bad thing to keep systems alive... But what's the use in having an alive, unreachable mail server? According to your statement you're blocking entire IP ranges, aren't you? Unfortunately this doesn't explain why some servers can connect to port 25 of mx.hispeed.ch while others on the same subnet can't? >From 217.26.52.23: Trying 62.2.95.11... Connected to mx.hispeed.ch. Escape character is '^]'. 220 mx.hispeed.ch ESMTP Sendmail 8.12.6/8.12.6/tornado-1.0; Thu, 29 Jan 2004 15:53:30 +0100 >From 217.26.52.15: Trying 62.2.95.11... telnet: connect to address 62.2.95.11: Connection timed out So your statement sounds kind of incomplete to me... Have you implemented other 'protection' mechanisms? Cheers, Markus ---------------------------------------------- [EMAIL PROTECTED] Maillist-Archive: http://www.mail-archive.com/swinog%40swinog.ch/
