The Email Standards Project launched last week. This group is looking to lobby and encourage companies to make their email clients comply with HTML display standards. They are also identifying how different clients display email with HTML. Check out their website, and see what they’re doing.
I do apologize for the light blogging recently. I have a couple big deadlines on my plate. I hope to get back to regular blogging soon.
Over the last couple days multiple people have asserted to me that Yahoo is greylisting mail. The fact that Yahoo itself asserts it is not using greylisting as a technique to control mail seems to have no effect on the number of people who believe that Yahoo is greylisting.
Deeply held beliefs by many senders aside, Yahoo is not greylisting. Yahoo is using temporary failures (4xx) as a way to defer and control mail coming into their servers and their users.
I think much of the problem is that the definition of greylisting is not well understood by the people using the term. Greylisting generally refers to a process of refusing email with a 4xx response the first time delivery is attempted and accepting the email at the second delivery attempt. There are a number of ways to greylist, per message, per IP or per from address. The defining feature of greylisting is that the receiving MTA keeps track of the messages (IP or addresss) that it has rejected and allows the mail through the second time the mail is sent.
This technique for handling email is a direct response to some spamming software, particularly software that uses infected Windows machines to send email. The spam software will drop any email in response to a 4xx or 5xx response. Well designed software will retry any email receiving a 4xx response. By rejecting anything on the first attempt with a 4xx, the receiving ISPs can trivially block mail from spambots.
Where does this fit in with what Yahoo is doing? Yahoo is not keeping track of the mail it rejects and is not reliably allowing email through on the second attempt. There are a couple reasons why Yahoo is deferring mail.
Charles Stiles, who managed the postmaster team at AOL and was laid off 2 weeks ago, is the new VP of Worldwide Business Development at Goodmail.
Ken Magill mentioned the possibility of Charles moving to Goodmail yesterday.
Sorry about the slowness, this server is the same one that is hosting thewholeinternet.wordtothewise.com and it got posted to digg today.
If the traffic storm keeps up for more than a day or two we’ll make other arrangements for the blog.