Rule Conditions for Automated Split Testing, API Key Security, and Dedicated IP Management

This week, we've focused on giving you more power when sending and helping keep your account secure. With additional conditions for the rules engine, you can set up more complex schemes, including automated split testing. You can also IP- and scope-limit API keys, and add more dedicated IPs to your account.

Nested Rules

Rules give a sophisticated (but non-programming) user a way to change the behavior of their transactional email. A common request is the ability to handle automated split testing without requiring changes to the sending code. We've added features this week for managing rules that make automated testing possible, as well as help manage your rules more effectively.

The fact that each rule can only match one event and take one action causes a lot of repetition as the same conditions are duplicated between different rules. First, your rules can refer to other rules in their conditions. For example, here are rules that send Gmail password reset emails to a webhook:

Since you can now set up rules that are only meant to be used as conditions in other rules, it's important that these nested rules don't accidentally modify your emails or trigger webhooks accidentally, so we've added a new action for rules called "do nothing." This can be used any time you want to keep a rule around, but don't want it to take any action.

Random Sampling with Rules

Sometimes you want to make a change to your email, but you're not sure if the change will be effective. Will it be delivered? Will people click more, or will they click less? Maybe you want to do an A/B split test on your change, or maybe you want to limit the change to some small percentage of your emails as a trial. There's now an option to use random sampling as part of your rule conditions, in addition to the other criteria for the rule. Then you can take actions like changing the template or modifying Google Analytics tracking, and those changes will only apply to that random subset.

Here's a couple of example rules that define a simple A/B split test:

Once the test is generating data, you can use stats comparison reports to chart and compare the differences between the groups. When you're ready to pick a winner, just change the winning rule to match all the time and delete the others.

Random sampling is a very flexible, powerful feature that lets you do really sophisticated things with your emails. We're really excited to see what you come up with.

Limiting API Key Privileges

Sometimes, less is more. Mandrill has always supported multiple API keys per account, to make it easy to replace keys without interrupting access to your account. But API keys have been equally powerful: every API key has full access to your account, which might be undesirable. We don't usually think about ways to make our application less powerful, but in this case, being able to place additional restrictions on API keys gives you a lot more control over the security of your account.

API keys can be restricted in two ways: by IP address(es) where the key can be used and/or by API calls that the key is allowed to make. For example, you can create a key that can send email and edit templates, but that can't access any of your activity history or account details. If you want, you can even create a key that can do nothing but ping us - because hey, why not?

Manage Your Dedicated IPs

You can now make additional dedicated IP requests from your account details page. It's a little more than just a button, but just barely.

There's no limit on the number of IPs can you add to your account - as your traffic grows, you can keep adding more. We're also working on exposing more features of our mail routing logic, to give users with dedicated IPs more control over how their mail is delivered, so stay tuned.