The lead I almost deleted because it read like admin work

Found a message in my inbox last year that had been sitting there for eleven days. Not in spam, not buried in a folder, just sitting in my regular inbox between a staffing schedule and a supplier invoice. Three sentences. No urgency in the tone at all. Turned out to be someone wanting to set up a recurring referral pipeline, not the one-off question I assumed it was from the subject line.
What got me was realizing I do this constantly. I triage messages by tone before I've actually processed what they're asking. Anything that sounds calm or administrative gets read last, sometimes never. Anything that sounds urgent or excited jumps the queue. Problem is, real opportunities don't always show up sounding excited. Sometimes the person delivering the best thing that'll happen to your business this quarter has no idea that's what they're doing, so they write like it's routine.
I went back and counted my last ten "real" opportunities. Three of them had been sitting in threads I'd nearly ignored or answered with one flat sentence. Not new leads I needed to go find. Leads I already had, in conversations I'd already started, that I just wasn't reading closely enough.
I built a small habit around this: once a week, fifteen minutes, I reread everything I marked low-priority that week with one question in mind — what is this person actually asking me. It's caught two things already that I would've missed entirely.
Curious if anyone else here has a story like this. What's the least urgent-looking message that turned out to be the most important one you got that month?