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Tag: dns

December 2016: The Month in Email

Happy New Year! We’re looking forward to some interesting new projects this year, both for our clients and for Word to the Wise. Stay tuned! December was a slow month for blogging, with everything going on. But we’re back on the horse now and ready to blog for 2017. List and subscription management continue to […]

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Is your website up? Are you sure?

“What would you do for 25% more sales?” It’s panicked gift-buying season, and I got mail this morning from Boutique Academia, part of their final push before Christmas. They’re hoping for some Christmas sales in the next three days. They do make some lovely jewelry – ask Laura about her necklace some time – so […]

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DNSBLs, wildcards and domain expiration

Last week the megarbl.net domain name expired. Normally this would have no affect on anyone, but their domain registrar put in a wildcard DNS entry. Because of how DNSBLs work, this had the effect of causing every IP to be listed on the blocklist. The domain is now active and the listings due to the […]

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HE.net DNS problems

Hurricane Electric had a significant outage of their authoritative DNS servers this morning, causing them to return valid responses with no results for all(?) queries. This will have caused delivery problems for any mail going to domains using HE.net DNS – which will include some of their colocation customers, as well as users of their […]

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The Internet is hard.

There are so many things that need to happen to make the Internet work. DNS entries need to be right. MXs need to be set up. Web servers need to be configured. And, let’s be honest, anyone who has ever run their own services on the Internet has flubbed a configuration. We don’t think about […]

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SPF: The rule of ten

Some mechanisms and modifiers (collectively, “terms”) cause DNS queries at the time of evaluation, and some do not. The following terms cause DNS queries: the “include”, “a”, “mx”, “ptr”, and “exists” mechanisms, and the “redirect” modifier. SPF implementations MUST limit the total number of those terms to 10 during SPF evaluation, to avoid unreasonable load […]

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TXTing

On Friday I talked a bit about the history behind TXT records, their uses and abuses. But what’s in a TXT record? How is it used? When and where should you use them? Here’s what you get if you query for the TXT records for exacttarget.com from a unix or OS X command line with dig […]

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A brief history of TXT Records

When the Domain Name System was designed thirty years ago the concept behind it was pretty simple. It’s mostly just a distributed database that lets you map hostname / query-type pairs to values. If you want to know the IP address of cnn.com, you look up {cnn.com, A} and get back a couple of IP addresses. […]

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PTR Records

PTR records are easy to over look and they have a significant impact on your ability to deliver mail without them.  Some ISP and mailbox providers will reject mail from IP addresses that do not have a PTR record created. PTR records are a type of DNS record that resolves an IP address to a […]

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4 things spammers do legitimate marketers don’t

I’ve never met a spammer that claims to be a spammer. Most that I’ve met claim to be legitimate marketers (or high volume email deployers). But there are things spammers do that I never expect to see a legitimate marketer doing. I’ve written about these things throughout the blog (tag: TWSD), but it’s probably time […]

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  • AOL FBL change

    Reminder for folks, AOL is changing their FBL from address starting on Jan 17th. AOLlogoForBlogThe (in)famous scomp@aol.net is going away to be replaced by fbl-no-reply @ postmaster.aol.com. These messages will be signed with the d= mx.postmaster.aol.com. Time to update your scripts!No Comments


  • Vague reports of Yahoo problems

    A number of people, on different forums, have been asking if anyone is seeing a higher bounce rate than usual with Yahoo. Not sure exactly what's going on here. As I understand it, folks are talking with Yahoo about it. If I hear anything more, I'll share. For now, though, if you're seeing a small increase in Yahoo bounces (or other weirdnesses) others are seeing something odd, too.No Comments


  • Responsive design just got easier at Gmail

    Today Gmail announced they are supporting media queries in Gmail and Google Inbox. This should simplify the creation of emails for multiple platforms. The full list of supported rules can be found on the Google Developer Site.No Comments


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