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Verizon's new spam filter causing some problems

Interesting discussion going on over at Slashdot and Google, about how Verizon has implemented a new spam filter that seems to be blocking all messages from gmail outright. These things come and go, so I predict this will pass.

April 25, 2006 in Spam Topics | Permalink | Comments (0) | TrackBack

Challenge-response spam filters


Whenever you send an email newsletter or promotional campaign, you get all kinds of bouncebacks.

That's why it's really important to use a reply-to email address that a human in your company actually checks on a regular basis. Especially the few minutes immediately after clicking "Send."

We just sent our MailChimp Newsletter, and within 10 seconds got half a dozen "I'm on vacation replies."

But mixed in with those autoresponders, we always find one or two "challenge-response" spam filter replies. If you're new to email marketing, and you're not familiar with challenge-response spam filters, read on...

Here's how challenge-response systems work.

You send someone an email. His spam filter says, "Hmmm, I don't recognize you." The spam filter sends you back a reply with some kind of question, like "how many puppies do you see?"


If you answer correctly, it proves you're a human (and not some kind of spam-bot), and you're added to the recipient's "approved" list. Once you're on the list, you never have to do it again.


Here's some information about one popular challenge-response system, MailFrontier Desktop.

There are other challenge-response systems that require you to answer a question, but then they also give you an opportunity to send a brief message to the recipient, so he'll be reminded of who you are (Earthlink uses this approach). For example, I once met with a potential client, then sent a followup email after the meeting to thank him for his time. I got an Earthlink challenge-response email, asking me to provide a little explanation of who I am.

So you really can't just blast out a campaign and walk away. Make someone responsible for checking the bounces, and be sure to tell them how to respond whenever they get a challenge-response email.

April 25, 2006 in Spam Topics | Permalink | Comments (3) | TrackBack

Subject Line Experiment

Th_gourmet In our Subject Line Comparison Study, we found that brief, matter-of-fact subject lines got better open rates than "salesy" ones. To further test our findings, we conducted a little experiment with long-time MailChimp user

They were planning to send this Easter promotion to a list from their customer database (we don't want to reveal too much, but the list was in the thousands---plenty for an experiment). The promotion was for free shipping, which is a pretty strong offer.

We split the list in half, and tested 2 different subject lines to see what open rates they'd get...

Subject Lines we tested, and the resulting open rates:

  • "Free Shipping this Easter - Offer Code Inside" (13% open rate)
  • "Free Shipping - Happy Easter" (16.6% open rate)

As you can see, the brief subject line was a 28% improvement over the long, salesy one with "offer code inside." They both pretty much say the same thing: "Free shipping this Easter." But the 1st one throws in that "offer code inside" line, which makes the whole thing sound like an ad. And nobody needs another ad in their inbox, do they?

How are your subject lines written? Do they tell what's inside, or do they sell what's inside?

Finally, we want to thank GourmetStation for letting us experiment with their campaign. Mothers Day is coming, and if you're looking for a nice gift, you should try one of their chef-prepared gourmet meals. Over the years, we've ordered almost every single meal on their menu, and they're delicious.

April 24, 2006 in Tips, Tricks, Best Practices | Permalink | Comments (4) | TrackBack

Broken "mailto:" links in Gmail

You know how you can use "mailto:" in a hyperlink to open up someone's email application? People do it a lot when they want to make it easy for someone to reply to them (such as from an HTML email).

Example 1:
<a href="">Email me</a>

Some of you probably know that you can add a subject line to that code with:

Example 2:
<a href=" is a subject line">Email me</a>

And then you can even add a message to the BODY of that email with:

Example 3:
<a href=" is a subject line&body=Here's some text for the body of the message.">Email me</a>

Pretty neat, huh? You can even use this as a quick trick for "forward this to a friend" in your emails.

Well, Example 3, where you add a message to the body of the email, doesn't work in Google's Gmail. The entire hyperlink seems to be erased, leaving nothing but un-clickable text. Examples 1 and 2 work fine in Gmail. You can use mailto: links with subjects embedded in them, but not the body.

Yeah, sort of an obscure HTML email tip, but that's exactly what this blog is for! A big thanks to the folks at GoodScreenMedia for pointing this out to us.

April 20, 2006 in Tips, Tricks, Best Practices | Permalink | Comments (2) | TrackBack

Do Benefits Headlines Still Work?

Found this interesting post over at the Blog. He lists some reasons why writing benefits into your headlines just doesn't seem to work anymore.

Reason #2: Your benefit head screams, “THIS IS ANOTHER AD!”

I think you can apply these same ideas to email subject lines.

How many emails come into your inbox every day? For me, it's about 500 or so (that's just at the office). For my business partners, they get a few thousand a day (because they manage so many websites). People are constantly bombarded by advertising, so why would they open another email with a subject line that screams, "THIS IS ANOTHER AD! OPEN ME!"

We recently compared subject lines from over 40 million emails sent from MailChimp, to see if we could find any correlation between subject lines and open rates. We found that the best subject lines tell what's inside, while the worst subject lines sell what's inside. Click for some examples.

April 19, 2006 in Tips, Tricks, Best Practices | Permalink | Comments (0) | TrackBack

MailChimp Study: Best and Worst Subject Lines by Open Rate

How do you write an email subject line that makes people open?

We just did a study where we analyzed over 40 million emails sent from MailChimp, and we compared the subject lines from the campaigns with the best open rates (60-80%), and the campaigns with the worst open rates (1-14%).

What did we find? The best subject lines simply tell what's inside. The worst subject lines sell what's inside.

See some real examples of the most effective subject lines, and some examples of the stinkers (don't worry, we disguised all company names)...

April 15, 2006 in MailChimp News | Permalink | Comments (1) | TrackBack


Hovering_cow Being an email marketing tool for "design-it-yourselfers" has its perks.

Mainly, it attracts a lot of very cool customers. One of our favorite examples is

By day, Mark Brabant is a self-employed graphic designer. By night, he sells t-shirts and screenprinted serigraphs that "deal with the paranormal in a tasteful, serious way." His "crop circle" t-shirts are pretty darn cool, and those posters of the hovering dog and cow are great (we're ordering some for our office here at The Rocket Science Group).

HoveringObject's Email Newsletter

Mark uses MailChimp to send email newsletters to his customers and friends whenever he has new work posted in his gallery. Here's an example of one of his emails.

It's yet another nice example of a modification to one of our free HTML email templates.

Want to see more examples of our creative MailChimp customers? We've showcased cranky pizza makers, kickboxers, fasion designers, universities, tea bars, and more in our Customer Showcase.

April 15, 2006 in Email Design | Permalink | Comments (0) | TrackBack

Email Marketing Resources

We just created an "Email Marketing Resources" page over at It's a list of all our favorite blogs, websites, downloads, and resources. Some of the sites are classics (sites we bookmarked and visited religiously when we first got into email marketing). Some of the links go to best practices guides from anti-spammers and email authorities.

Hope you find it useful. If you've got a blog, website, or article you'd like listed, please let us know

April 15, 2006 in MailChimp News | Permalink | Comments (0) | TrackBack

Showcase: Texas Hearing and Service Dogs

We posted our free HTML Email Templates back in February, and so far, they've been downloaded over 3,000 times. Not too shabby!

When we launched the templates, we asked for some email newsletter "makeover" volunteers. Sort of like MTV's "Pimp My Ride" but with less chrome.

Our first "Chimp My Newsletter" showcase is from Texas Hearing and Service Dogs. Here's a description of what they do: "Texas Hearing and Service Dogs (THSD) adopts dogs from animal shelters and trains them as working partners for Texans living with disabilities — free of charge. " Tell me that's not a cool organization. Those dogs are awesome. If I ever saw one of those orange-vested dogs on the street, I'd definitely stop and salute.

Anyways, we redesigned their email newsletter by using one of our standard templates (the 2-column style template, to be specific). All it takes is some tweaking of the CSS,  some image files, and a few font changes, and presto: The New Service Dogs Email Template.

It's pretty neat to compare the standard template to the final, customized design. You get a feel for how versatile our templates can be.

And since MailChimp gives you full control over the code in your sign-up form (see screenshot), we took the default sign-up form and "Chimped it up a notch." BAM! Here's the new Service Dogs Newsletter sign-up form.

We've got a couple more "Makeovers" in the works, and will post them here soon. If you've downloaded and tweaked our HTML email templates and want to show them off here, let us know.

April 12, 2006 in MailChimp News | Permalink | Comments (0) | TrackBack

MailChimp Nominated for a Webby Award (seriously)!

So I almost spit coffee all over my monitor this morning when I opened up my email and learned that MailChimp was nominated for a Webby Award. Cool! We're up for an award in the "IT/Hardware/Software Website" category.

Then I almost spit out more coffee, when I saw who the other nominees were:


There are basically 2 ways we can win. First, we could win the "official" award from the Webby judges. Looking at who we're up against, I don't think those guys have a chance against MailChimp. I mean, who ever heard of "IBM"? So we're pretty much a shoo-in for that.

It's The People's Voice Award that we're concerned about. That's where the general public can voice their opinions about who should win. We need as many people as humanly possible to vote for MailChimp. Yeah, I'm shameless. But MailChimp had his first taste of victory back when we got the WebAward, and now he's got an insatiable blood-thirst for more trophies and certificates. He will not stop until he's won every single web award, cooking contest, and spelling bee in the country. Besides, how funny would it be for a chimp to beat out those fat-cats?

If you'd like to help spread some "Monkey Love," vote for the 'chimp here:


And if you're so inclined, here's a badge you can stick on your website. We'll probably build a landing page one day soon, but until then, you can point to our permalink here:


Our first sighting for the "Vote M" badge: Bucket Republic. Thanks, Matt!

April 11, 2006 in MailChimp News | Permalink | Comments (0) | TrackBack

MonkeyBrains! is the official MailChimp Blog. MailChimp is a product of The Rocket Science Group.