How to test different “From” names or reply-to addresses?

Testing sender identity variations:

From name testing: Send identical content with different From display names ("John at Company" versus "Company Sales"). Measure placement differences.

Reply-to testing: Vary reply-to addresses while keeping other elements constant.

From address testing: Test different From addresses if you have multiple sending identities.

Sender identity typically has less impact than reputation and engagement, but can affect user behavior and indirectly influence placement through response patterns.

Test whether flying a different flag changes your port reception.