Although the log-checking process would work, this one is likely the fastest solution for most situations.

... although I'd move the $condition_requires_email to an outer if block that wraps the whole thing ... otherwise, your logic would send e-mail when (!$condition_requires_email)

I don't know what type of NRT data bfdi533 is dealing with, but with the space weather data that I deal with, getting the alerts out without a potential 1 hr delay is quite important. (and contractually required, according to the mission's PDMP (Project Data Management Plan)).