On Mon, 2004-12-06 at 10:24 -0400, Chris Mason wrote: > You advice is well received and the linked HOWTO is excellent. However, I > don’t know if I want to move to postfix, is ther eany reason to do this, and > if I don’t, what would be different in configuring sendmail to deliver to > the dovecot maildir format? First, Postfix is an excellent mail server. Maildir format is superior to mailfile format in a few ways, but there is one problem (I think) with Postfix that I already have with Qmail. Next time I will go with Courier email. I use that IMAP server now and it works great. I have been using Qmail since '96 or so. It is secure and fast. It's only drawback, and I think that Postfix shares this issue (let me know if it does not), is that it receives all messages sent to it before it bounces the messages. This means that if you suffer a dictionary email attack and you bounce mis-addressed email, you could end up with a million outgoing messages in your queue. This might sound far fetched, but I have three domains which receive close to 30k emails a day to users who do not exist. Some other mail servers, like Courier, look at the addressee of incoming email and do not accept the email if the user does not exist. The next issue comes up with email and spam/virus checking. Processing 30K messages on a Qmail machine with no spam/virus checks are easy. You can probably do it with a 400Mhz machine and 128MB of ram. If you want to spam/virus check that number, though, you need more resources. Can you block the dictionary attack by cutting off the server? Probably not this attack since I get no more than 25 pieces from any one host! This is a very distributed attack. Will this happen to you? Who knows. I never thought It would happen to me. This obviously comes from a network of compromised machines. -- Ed Weinberg -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
