How well do you parse out message bodies for every email provider out there? I spent quite a long time making sure my bot can handle different email services and ensuring it’s getting the message body without all the other unnecessary text.
That would be useful for the drab use case of end to end testing. Every team had probably half arsed a test that needs to check an email inbox via smtp.
I used to use https://www.mailslurp.com/ for that purpose and it worked fairly well. IIRC they even had a long-lived Keep-Alive endpoint where you would make a GET request and it would sit and wait for up to a few minutes until a message arrived.