October 2007
Intermediate to advanced
1308 pages
161h 13m
English
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Finer Control with V8.10
Prior to V8.10, the lefthand side of the
access database could contain
only a user, host, domain, or address, and would
only look them up based on the client name or
address, the MAIL
From: address, or the RCPT To:
address.
Beginning with V8.10, sendmail offers much finer control of addresses and rejections in the access database. The lefthand side of the access database can begin with one of three possible prefixes:[132]
Connect:The address is either the IP address or the hostname of a connecting host.
From:The address is that of an envelope sender.
To:The address is that of an envelope recipient.
When an address is looked up in the access database, it is first looked up with the prefix. If it is not found, it is looked up again without a prefix, meaning that the old access databases will still work with newer versions of sendmail. To illustrate, consider this update to the access database shown in the previous section:
From:spamuser@hotmail.com REJECT From:cybermarkets.com REJECT Connect:example.org REJECT Connect:192.168.212 REJECT
This access database will cause mail from spamuser@hotmail.com to be rejected. Mail from any user at cybermarkets.com will be rejected, connections from the host example.org will be rejected, and any mail from any host with an IP address ranging from 192.168.212.0 through 192.168.212.255 will have the initial connection rejected. In that last example, any missing righthand part of an IP address is assumed to be a wildcard for matching ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.