Has your email ever become eerily silent? As in empty. You're not getting any. That happened to me recently. I was getting messages in some accounts, so I just thought I wasn't getting any mail --- until my wife sent me a message and I didn't get it. I use Thunderbird for a client, so usually I just click the button to get all messages, assuming I was getting all messages. After I didn't get her's, I told Thunderbird to get the messages for just that account. Thunderbird asked me for my password.
What?! Yep. Somehow the passwords for half my accounts were lost. I re-entered all of them, downloaded the mail, and found myself inundated.
Maybe I was better off being blissfully ignorant.