Recently, an abuse desk rep asked what to do when customers were complaining about being assigned an IP address located on a blocklist. Because not every blocklist actually affects mail delivery it’s helpful to identify if the listing is causing a problem before diving in and trying to resolve the issue. Find out whether mail is actually being blocked, or whether the customer just went to...
It can be difficult and frustrating for a sender to understand they whys and wherefores of spam filtering. Clearly the sender is not spamming, so why is their mail getting caught in spam filters? I have a client that goes through this frustration on rare occasions. They send well crafted, fun, engaging content that their users really want. They have a solid reputation at the ISPs and their inbox...
We run top-level DNS servers for several blacklists including the CBL, the blacklist of infected machines that the SpamHaus XBL is based on. We don’t run the CBL blacklist itself (so we aren’t the right people to contact about a CBL listing) we just run some of the DNS servers – but that means that we do get to see how many different ways people mess up their spam filter...
There is a lot of mythology surrounding spamtraps, what they are, what they mean, how they’re used and how they get on lists. Spamtraps are very simply unused addresses that receive spam. They come from a number of places, but the most common spamtraps can be classified in a few ways. Addresses that used to belong to someone and subsequently abandoned. This is where a lot of spamtraps at...
“What should we tell the ISP?” is a frequent question from my customers. The answer is pretty simple. It doesn’t usually matter what you tell the ISP. What matters are your actions. If a sender is having delivery problems then the solution is not to call the ISP and talk to them about why the sender’s mail should not be delivered to the bulk folder. Instead, the solution...
MediaPost had an article written by George Bilbrey talking about how 2010 could be a difficult year for marketers with marginal practices. George starts off the article by noticing that his contact at ISPs are talking up how legitimate companies with bad practices are causing them problems and are showing up on the radar. This is something I talked about a few weeks ago, in a series of blog posts...
Yesterday I talked about how I’m hearing warnings of a coming paradigm shift in the email industry. While these changes will affect all sender, ESPs in particular are going to need to change how they interact with both ISPs and their customers. Currently, ESPs are able to act as “routine conveyers.” The traffic going across their network is generated by their customers and the ESP only handles...
I was reading an article on Virus Rants and the opening paragraph really stood out. you wouldn’t think this needs to be said, but apparently it does – being a whitehat means taking sides. more than that, it means taking the side aligned (more or less) with the general public’s interests – doing things for their direct or indirect benefit. In the ISP world most sentences...
How much control over delivery do senders have? I have repeatedly said that senders control their delivery. This is mostly true. Senders control their side of the delivery chain, but there is a point where the recipient takes over and controls things. As a recipient I can report your email as spam forward your email to another account on another mail system file your email in a mailbox I never...
People mailing to Cox in the wee hours of this morning may have received a rejection message citing the Invaluement DNSBL. 554 IMP a.b.c.d blocked. IPBL100 – Refer to Error Codes section at for more information. I spoke with one of the folks at Cox and they said there was an error in the implementation causing non-listed IPs to be rejected erroneously between about 4am to 8am (Eastern)...
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