Email tests in CI often fail for boring reasons, not exotic ones. The API sends the right event, but the workflow looks at the wrong inbox, waits too long for one step, or only asserts that "some message arrived". That is how teams end up shipping template regressions even though the pipeline was green all week.
Why email checks break in otherwise good CI
The weak spot is usually the contract between your API and the job that validates the notification. If the contract is fuzzy, the workflow gets fuzzy too.
I see the same issues over and over:
The test only checks subject text, so an older message can still pass.
