I’ll generally accept it if you send any excuse prior to the lecture unless it’s becoming a habit - in those rare cases I’ll happily work with them to try and figure out a solution. 80% of the time it’s family medical appointments or childcare scheduling issues (and my gosh I am so happy to accommodate people dealing with that) and the rare cases it’s not we can usually find a way to make up for what they’ve missed. I’ve got a couple colleagues that only accept excuses with a doctor’s note, and the best thing I can say about them is that they’re retiring soon incredibly passionate about teaching.

(none of this applies to freshman courses, though. We’ve learned that being really strict about attendance for freshman year boosts passing rates by like 30%, it’s just crazy.)