I've got a test instance of a compiled web app (that I didn't write) which I'd like to do some testing with, however the app contains client email addresses that I would like to not receive emails while I do said testing.
Right now, this web app uses a particular SMTP server — call it
mail1 — to send out notification emails when various events happen. To minimize the amount of customization I would need to do to the app or its data (which may skew the testing), I'm thinking a solution to avoiding sending these emails might be to stand up a temporary SMTP relay
mail2 that inspects the outbound email addresses and only relays emails to
Is this the sort of thing I could do with Postfix or Qmail? If so, are there any recommendations for how to get started doing this? I've never configured either before, and I'm wondering if there's perhaps an entirely different mail-limiting solution that I'm overlooking. Maybe even something Gmail/Google Apps can do?