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Our design and spam testing tool has been a super popular feature since we launched it a year or so back. For many of you it’s a crucial part of the design process for each campaign you send. Because of this, it can get frustrating when that key email client isn’t returning any results. We’ve been working hard to make this a thing of the past, and I think you’ll like what we’ve come up with.

First, a bit of background


Building a service to generate screenshots in dozens of different email clients is a huge undertaking. We looked at our options, and after trying out a few services we partnered with the great folks at Return Path, the biggest provider in the industry (who do lots of other great stuff too).

Since that time, tens of thousands of spam tests have been run with thousands more added every month. As I said, a service like this is a challenge to maintain, so it’s not surprising that some email clients can take longer than others to return results. Unfortunately at times this can lead to a frustrating experience for our customers. When you’re working on a time sensitive campaign and need to see how it looks in Outlook 2007, you want that screenshot back in minutes, not hours or days. We understand that.

As the middle man in all this, it’s been a challenging time for us too. We know the Return Path guys are working incredibly hard to ensure they are always returning all screenshots in a timely manner. We know you need your screenshots returned in a timely manner. This got us thinking hard about what we can do as the middle man to make sure you get the best testing experience possible.

What about Litmus?


We’ve been big fans of the Litmus team for some time now. Their email testing service has come a long way in the last 12 months as they continue to add more email clients and spam testing services to their roster. We’ve been watching their service closely and were impressed with what we saw.

The initial plan was to try their service out internally and see if it was a viable alternative to Return Path. Every time you guys ran a design and spam test, we submitted it to both providers to see which one consistently returned the best results. In the end, it turned out there was no real winner. Return Path were quicker for some email clients, while Litmus was faster for others. We were left with a difficult choice.

That was, until Ben, our lead developer and co-founder asked the obvious question: “Why don’t we just use both services simultaneously?”

When two become one

In hindsight it seems crazy we didn’t think of this first, but by combining both providers into a single service for our customers, we can instantly provide the fastest, most reliable design and spam testing tool on the market today.

Every time you run a test, we fire off your campaign to both providers simultaneously and sit back to see which one returns each screenshot first. It’s like horse racing for nerds. Whichever one returns that screenshot or spam filter result first is displayed in your account. The beautiful part about this approach is the reliability side of things. There’s only a slim chance that both providers will have rendering problems with a specific email client at the same time. So, if Litmus isn’t returning Lotus Notes 6.5.4 right now, there’s a good chance that Return Path will be.

What about the cost?

This one wasn’t an easy choice. Obviously our costs for providing this service have just doubled. A number of other email marketing apps also integrate with Return Path, only they charge at least two or three times our current price. We had some room to move, but in the end decided that we weren’t comfortable passing this on to our customers. You guys shouldn’t have to pay more for a service that works like it always should have.

The test price is exactly the same as it always was, and we’re happy to lose our profit for the sake of a much better experience. Unfortunately, due to pressure from others providing similar services, we can’t share our prices here. If you log into your account, you’ll see they’re just as low as they’ve always been.

No more surprises

Even though we’ve merged the two providers into a single service, every so often both might be having trouble with a particular client. There’s nothing worse than paying for a test to see your email in a particular client, and that’s the one email client that isn’t returning results. We’ve put an end to that issue too.


Each time you run a test, we’ll provide a clear warning like the one above about any particular email client that’s been returning poorly across both providers. This way, you’ll know exactly what you’ll be getting for every test you run. Of course, if the key client you’re looking for isn’t available this isn’t much help, but at the very least we won’t be wasting your time and money.

New email clients and spam filters

By merging Litmus into our testing suite, we’ve also added some useful new email environments. Our Windows customers will be loving the addition of the two most recent versions of Apple Mail. We’ve also broadened our Lotus Notes support with the latest two versions, meaning we now cover all major releases from version 6.5.4 through to 8. Here are the additions:

  • Apple Mail 2.1
  • Apple Mail 3
  • Lotus Notes 7
  • Lotus Notes 8
  • Outlook 2000

Litmus also supports a number of new spam filters that we’ll also be running every test through, including popular web-based email providers like Yahoo! Mail and Gmail. Here’s the list of new filters now available.

  • AOL
  • Gmail
  • Hotmail
  • Outlook 2007
  • Yahoo!

We’re not stopping there

Now that we’ve got the biggest feature on the list done – reliability, we can get started on other cool ideas we’ve got cooking to make designing and testing your emails as pain free as possible. A big thanks to the team at Return Path and Litmus for all their help and patience as we worked hard to bring this all together. We think it was worth it, and hope you do too.

  • Jenn

    This is great :)

    Thanks for keeping the price the same. It is one of the reasons that we use Campaign Monitor for our clients.

    Reliable results. Thanks!

  • Kiryn

    thanks fellas, Same as Jenn, a reason i punch out emails with you fellas is the reliability…

    sure others are cutting corners and prices, but this is one example of paying peanuts and NOT just getting monkeys!.

    thanks for keeping it on the up & up!. you ROCK!,

  • James

    Excellent news guys!
    It would be good if you could persuade Litmus and/or ReturnPath to include Outlook Web Access as an email client for testing too…

  • David Greiner

    Thanks guys, appreciate the awesome feedback. James, that’s a great idea and I’ll be sure to pass it directly on to both the Litmus and Return Path team.

  • Anders

    Amazing post! You guys are second to none.

  • Oskar Rough

    Really, really nice work. It’s funny how you just discover Litmus/Alkaline and see this post the very same day – you guys are snappy!

  • David Greiner

    I agree Oskar, Alkaline was a great idea. I was lucky enough to beta test it and was very impressed. Very cool alternative for Mac designers.

  • Elliot Cooke

    All credit to you for keeping the prices the same. I don’t think any of us wouldn’t have liked to inform our customers of a price increase right now!

    Great work, great service as always. Thank you!

  • Jon Livingston

    Another example of great customer service. I really appreciate how you guys are continually helping us without trying to add additional costs. I/We really appreciate that!

  • Frances Dugan

    Wow, this is wonderful. It’s great to work with an ESP that really understands the wants and needs of its customers. Keep up the good work!

  • Damien Miller

    Excellent, now I can stop sending test emails to Litmus and do it directly from CM.

    P.S. Loving the Alkaline plugin for Coda!

  • Jon Moss

    Super stuff guys – impressed, as always.

    Best wishes from England!

    Jon :-)

  • Paul Masri

    I’m impressed with your dedication guys. Thanks for putting in the warning notice about clients not responding. As you say, it doesn’t help if we *need* one of those clients, but at least we know what’s happening and won’t sit twiddling our thumbs.

  • Paul Farnell

    Great write up, David. We’re really delighted to have our email testing service inside Campaign Monitor. We use CM for all our mailings internally, so we’re very excited about the partnership.

    We’ve got some very cool new email clients coming soon, including Outlook Web Access as requested above. We’re also working to enable email testing on a certain Apple device :) It’s great that these new email clients will be available not just to our own Litmus subscribers, but to all CM users too. We couldn’t be happier!

  • Simon

    I signed up yesterday, so I don’t have any prior experience. But I can say that the testing tools are now excellent. I had all the results back within an hour. MobileMe failed though – I don’t have a screenshot.

  • Wayne Powell

    I’ve never liked Litmus, their lack of business integrity for charging for an untested service has always kept them back as a serious contendor in my opinoin.

  • Steve

    Thanks Guys. This is why we love CM. Not only have you developed a great product, you keep on developing it! CM ROCKS!

  • Jason Millward

    Great work guys. Its never ceases to amaze me when you add another major improvement to a fantastic product.

  • LapyKing

    We just sent out our first campaign with you earlier this week and we are very impressed. And now you go and add more! Fantastic work.

  • Kevin

    The first time I saw the warning “AOL etc is not returning screenshots right now,” I thought I wasn’t going to get the pictures at all. I didn’t realize that it meant that they would be delayed. So maybe the wording could be finessed a bit. But I’m glad the screenshots will be coming faster! Yay!

  • David Greiner

    Kevin, sorry for any confusion there. We actually say that they won’t be available, as most of the time they won’t return anything. There is a chance they will, and we’ll display them if they do, but we don’t want to set false expectations, so we prepare you for the worse.

  • Jet Jagger

    David, this is great! Thanks for taking CS/CM to the next level!

  • Jeremy Glover

    I love you guys :)

  • Marcel Dietzmann

    Good work!

  • AJ

    This is amazing. I am impressed and my team will certainly like it.

  • Adrian Hill

    More great updates from CM. We need more companies to follow your ethos!

  • Matt Wilding

    Why haven’t you integrated with Pivotal Veracity? Based on our review, they are the only ones who truly cover mobile rendering.

  • Mary Beth

    You guys are the best out there. Please don’t stop being who you are! Love you customer service and your continual strive to add features for us to use.

  • Zeke Franco

    Nothing better than a company who strives to make my life easier. Thanks!

This blog provides general information and discussion about email marketing and related subjects. The content provided in this blog ("Content”), should not be construed as and is not intended to constitute financial, legal or tax advice. You should seek the advice of professionals prior to acting upon any information contained in the Content. All Content is provided strictly “as is” and we make no warranty or representation of any kind regarding the Content.
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