October 2007
Intermediate to advanced
1308 pages
161h 13m
English
Content preview from sendmail, 4th EditionBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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.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.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.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.
Locate the Public Key
Public keys may be distributed in many ways, but for email only four methods are available:
Public keys may be given to a recipient out-of-band, as, for example, by delivery of a floppy disk containing the public keys. Using an out-of-band method, the public keys may be stored long before the email is sent.
Public keys may be embedded in a message. Typically, they are located in the header part of a message as part of a special header. For example:
X-Public-Key: c3NoLWRzcyBBQUFBQjNOemFDMWtjM01BQUFDQkFKOTh2MXloQVp VWjBYM3ZMUVhiemVwY1hienkvdnh6T1NEN3E0a25Ed3loSWFoYm dLclMzK2RIV3hzOUErSTRrV2YrODlBLzMzU3VGOCtBOFdwUTc2W ld2K2JHMUZiUzg0WW5XeWtNUlY3Z3NzY2VlQUs4OXM2ZDcvSlR3 VDhiZi9OVTFlT2hvWUdjamJONFBHVHhHajB1bW9nWlBaRiswdEZ SMm45b3hVcFpBQUFBRlFDdGpUUVBCS016cXM1Y0QxZVAydXJEZX NXSERRQUFBSUFwMEg5dG9YZ21yekJJdjN0aUtVWWcrN0JvSndsW HdWTnNiR1lPcVlzdWpxUlZKUWQ0SXRlcVo1WVo2VG5Rbk5DZUho V2tjVFNPa3NFcVhsemlIemtudS9pRUp4MTloQnlYaXFzYmlQQ2V ZRU1pZUp2Z2crWWZVQTlXb0QwWk00bEs2VHhKUTB2U09PV3E0Yn ZFYzNCMzI3ZGh6dS9QaGNqenNNLzMzQ05pVHdBQUFJQXNMWVduU HFMNnVkNFR0RTRFYXIyVXBaQ282WEg1ZDk2cVRHNHhUdlpLMnpl NTVyRi9Rc1pXNVdod2ZvYkhRWmM5WlRRZzdMeFRtSFhDZmVHT1U 3eGhrTGpPUTJqMVB0ZXlYd2FTUVpiek1ITU8zaW10ejNwdVB4Vn J5a0owTVc0NHdPd1VzbWRvSElqOE5Za094QmNzU1FLUzN6NTdXb 0VOSnZKbFZuSjBjdz09IGJjeEBsYWR5Cg==Public keys may be downloaded. DKIM, for example, specifies that public keys be downloaded using DNS:
% dig txt mypub._domainkey.example.com
A special header may specify a web URL:
X-Public-Key-Location: https://www.example.com/keys/email/A459b.pub ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
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.