Lately it seems at least 75% of my emails to #gmail accounts go mysteriously missing. I don't know if they aren't arriving at all, or if they're just going straight to spam, or what, but gmail obviously doesn't like the address I'm sending from.
Aside from being annoying, this is a good demonstration of how centralised services are problematic. If 8 out of 10 people I email are all using gmail, and gmail mistreats my messages, then their error becomes the expected [de facto "correct"] norm.