Robert Penz writes:
The problem is that the spam seems to hit this server in waves which lead to more then 10 times the connection rate as normal. Almost all of the connections are blocked by the dns blacklist feature, but the connections are somehow not dropped at once. This leads to entries likeJul 18 09:57:12 mail courieresmtpd: 250 maximum active connections. and as courier seems to start a process per connection also in a high memory usage up to 1GB only for smtp.
It's a war of attrition. There's not much that can be done except to keep scaling up the system to cope with the load. It's not only SMTP, for example. DNS server operators, for example, often have no choice but overprovision their bandwidth and CPU to deal with attacks on DNS servers.
But it's really not a problem unless you're maxed out on connections for a prolonged period of time. SMTP is not instant messaging. If the sender cannot connect, the sender will try again later, so if this goes away before long, you won't really have any long term impact.
pgp5X9hmbpXxr.pgp
Description: PGP signature
------------------------------------------------------------------------------ Enter the BlackBerry Developer Challenge This is your chance to win up to $100,000 in prizes! For a limited time, vendors submitting new applications to BlackBerry App World(TM) will have the opportunity to enter the BlackBerry Developer Challenge. See full prize details at: http://p.sf.net/sfu/Challenge
_______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
