For companies using classic CheetahMail, there is not currently a programmatic way to test subject lines.

If you are a Cheetah Messaging user, Phrasee does have an integration available. If you're unsure if you're using classic CheetahMail or the newer Cheetah Messaging, check your login URL.

If you login using app.cheetahmail.com, you are using classic CheetahMail, and this support page is for you!

Within CheetahMail, there is a subject line testing feature, which allows you to set up subject line test scenarios manually.

You can create as many test cells as you'd like and can also designate a percentage of your selected audience for each test cell. CheetahMail will automatically calculate how many recipients will receive each subject line.

You'll want the numbers it calculates to match your recommended Phrasee experiment split numbers as closely as possible.

You then choose the metric you want to use for your winner selection. We recommend using highest unique open rate. CheetahMail will then send the remainder to the winning version after your specified wait period.

Generally speaking, we recommend a testing period of at least 4 hours. But every audience is different, so you should reach out to your Phrasee Customer Success Manager for help with determining your specific methodology.

You should also discuss with your Phrasee Customer Success Manager methods for returning your subject line test results to the Phrasee platform. We will work with you to make it as easy as possible to send us results.