… until it stops moving

gotzombie

Nothing is impossible to kill. It’s just that sometimes after you kill something you have to keep shooting it until it stops moving.Mira Grant, Feed

It’s getting to the time of year when I can get away with some horror movie metaphors. Today, things that are dead.
1. ADSP
ADSP was a domain repudiation scheme that should never really have lived, but thankfully it’s now dead. If you see “_adsp._domainkey” in DNS somewhere, kill it with fire.
(Don’t confuse it with DMARC, it’s much improved spiritual successor.)
2. SenderID
SenderID was a slight variant of SPF created by Microsoft and pitched for a while as “SPF version 2”. If you see “spf2.0/” in a DNS TXT record, beat it down with a shovel.
3. DomainKeys
DomainKeys served valiantly as a prototype, but has been entirely replaced by it’s successor, DKIM. Nobody is paying any attention to DomainKeys signatures, certainly not for mail that’s also signed with DKIM.
It’s dead. Completely dead. So if you see “DomainKey-Signature:” in an email somewhere, shoot it until it stops moving.
 
 

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I’ve been seeing reports over the last few days about an increase in bounces at Yahoo. Reliable people are telling me they’re seeing some increase in “invalid user” bounces.
You may remember Yahoo announced an overhaul of their mail product back in December. Reliable sources tell me that this is more than just interface revamp. In the back end, Yahoo! is removing older products with few users and security problems. This fits in with the changes CEO Mayer has been making with the company: slim down and stop supporting unprofitable products.
It makes sense that while engineers are looking at the guts of the email program and cleaning up the cruft, they will also disable long unused email addresses. This will result in higher unknown users for some senders.
What’s interesting to me is that the reports are somewhat sporadic. Some senders are seeing a huge percentage of bounces, some are seeing the normal percentage. I expect this difference isn’t anything more than how actively a sender purges based on engagement. Senders that purge unengaged addresses are going to have already removed a lot of the addresses Yahoo! is now purging from their database. Senders that keep sending to their whole list, are going to see a lot of unknown user bounces.
I’ve asked a few folks and people who’ve responded told me that spot checks showed all the addresses turning up as invalid had no engagement for long periods of time.
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Q: How many email addresses are affected?

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