The new MailChimp is live. For the most part, the launch has been one of our largest— yet somehow smoothest—upgrades ever. Especially when you consider that every single line of code has been completely replaced, and we were dealing with about 7 years of legacy data.

So far we’re getting some great reviews for the new design and functionality. The Ajaxy interface is much easier and faster than the old MailChimp, the new HTML email designer is a huge improvement, and the video tutorials peppered throughout are a big hit.

The new architecture is infinitely more scalable than our old code—so much so, that we’re already adding new features (I’ll post about them shortly) and plugging in more servers.

The launch wasn’t completely perfect. Migration continues to be a challenge. Out of about 45,000 accounts, 1,700 haven’t finished migrating from v2 to v3 yet. They’re still migrating as we speak. We hope to have every account 100% migrated soon, and we’re formulating a plan for people with extremely urgent campaigns (customers, we’ll be sending you an email update shortly).

We’re posting detailed server & migration updates via Twitter.

Later in the week, we’ll be posting screenshots and details about new features in v3. But for now, we’re all too busy getting accounts migrated over. Stay tuned!

I sent this out as an email to all our customers, but just in case, I’ll post it here:

Sorry to keep repeating ourselves, but when we bring the server down, we really want to make sure all our customers know about it ahead of time.

Tonight (Friday, May 16th) we will begin the v3 launch sequence at 10pm ET. For our friends across the pond, that’s:

• Melbourne time = Saturday at Noon
• London time = Saturday at 3am
• Paris time = Saturday 4am

The new MailChimp application will go live instantly at 10pm.

However, it will take the entire weekend for your account to be migrated over to the new application.

So what that means is if you come to MailChimp.com tonight, you might see that we’re live, but you won’t be able to log in.

Your account should be live and ready to go in v3 by:

• Monday 9am Eastern time
• Monday 11pm Melbourne time
• Monday 2pm London time
• Monday 3pm Paris time

We are doing everything in our power to make this a smooth transition. We’ve prepared for months. We’ve practiced for weeks. We’ve got backups of backups of backups. It might be a bumpy ride (servers are never fun to deal with), and we do appreciate your patience through all this.  When we’re live and the dust has settled, v3 is going to be a huge improvement. What’s cooler is the foundation will be in place for much faster, more scalable innovation (more useful features for you, faster).

If you have no idea what we’re talking about, or haven’t had time to read about it, please learn more about MailChimp V3 here. There are demo videos that show you what will change, and how to use the new MailChimp. We’ll also be hosting webinars next week, to show you how to use the new MailChimp.