Same, I'm using it in CI/CD for full E2E tests of web apps in combination with Playwright for app interaction, and it's awesome. Same test flow can nicely simulate user interactions and verify that emails with the correct content go out from the backend, all in seconds within a normal Gitlab CI test job.

May take a look at Mailpit though. It has the advantage of having a native Docker image build, whereas for Mailcatcher I'm using a third-party Alpine-based image.