Legit Email is always classified as spam

I’d like some advice. I am often waiting for emails from the post, when I expect a package delivery. Track and Trace updates, and eventually the notifications to collect the package from the office.

For over a year now, these are always classified as spam, and I had to give them the thumbs up each and every single time. Is this spam detection functionality one that doesn’t learn? How do I whitelist a sender for good? Please help, with the influx of false positives/negatives I get with this spam detection, I’m feeling some frustration by now.