Send Bulk Mailing or use A/B testing
You create a new Civimail at this link.
A/B testing allows you to send two test mailings to a random subset of your recipients. After collecting and comparing metrics, the more successful mailing will be sent to the remaining recipients. You can test
- different "Subject" lines
- different "From" lines
- different emails
To undertake A/B testing visit this link and set up the test, specify what percent of the mailings go to A, B and Final, select your target Group, and then compose the emails with the variations.