I’ve seen this trick used by a few senders recently, with varying effectiveness. Where do they get these pictures? While you can scatter any images you like across the body of your message, the subject line is limited to just text. But “text” is more than just “a, b, c” – using RFC 2047 encoding you can use any character you like, including many tiny pictures...
After they were a a little embarrassed by their own DKIM keys being poorly managed a few months ago, Google seem to have been going through their inbound DKIM handling and tightening up on their validation so that badly signed mail that really shouldn’t be treated as DKIM signed, won’t be treated as signed by Gmail. This is a good thing, especially as things like DMARC start to be...
Email – and email filtering – makes a lot of use of DNS, and it’s fairly easy to miss something. Here are a few checklists to help: Data you need before you start: [table] Information,for example Return path / bounce address,bounces.myesp.com Mailserver hostname,mail4.myesp.com Mailserver external address,192.0.2.4 DKIM “d=”,greatbigmarketer.com DKIM selector,oct2012...
You can trust the “experts” that populate Facebook. Or you can take An Introduction to Computer Networks from Stanford University. This is an introductory course on computer networking, specifically the Internet. It focuses on explaining how the Internet works, ranging from how bits are modulated on wires and in wireless to application-level protocols like BitTorrent and HTTP. It also...
Facebook hosted a DMARC interoperability event earlier this week. In terms of protocol development, interoperability events are a sign that the protocol is ready for more widespread use.
DMARC is a layer built on email authentication (SPF and DKIM) that provides brands with the ability to control use of their domains in email.
This morning was the final flight of the Space Shuttle Endeavor. In fact, it was the last flight of any shuttle ever, anywhere. We were lucky enough to get passes to NASA Ames Research Center at Moffett Field to watch the flyover.
Technology is so awesome. Sometimes we spend so much time sweating the details, we miss the bigger picture.
Godspeed, Endeavor.
Email is a “store and forward” protocol. The sender doesn’t connect directly to the recipient to send the mail with just one network hop, rather the sender connects to a mailserver (usually referred to as an “MTA”, short for Mail Transfer Agent) and sends the message there. Once that MTA has received the message it sends it on to another MTA, and so on until it...
More than just PGP Cryptography is the science of securing communication from adversaries. In the email world it’s most obvious use is tools like PGP or S/MIME that are used to encrypt a message so that it can only be read by the intended recipient, or to sign a message so that the recipient can be sure of who it came from. There are quite a few other aspects of sending email where a little...
Much like every other day, I got some spam today. Here’s a lightly edited copy of it. Let’s go through it and see what they did that makes it clear that it’s spam, which companies helped them out, and what you should avoid doing to avoid looking like these spammers… Received: from [213.144.59.132] (114.sub-75-210-142.myvzw.com [75.210.142.114] by m.wordtothewise.com...
This is a great story from Trey Harris about a real email delivery issue from the mid 1990s. Here’s a problem that sounded impossible… I almost regret posting the story to a wide audience, because it makes a great tale over drinks at a conference. 🙂 The story is slightly altered in order to protect the guilty, elide over irrelevant and boring details, and generally make the whole...
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