Whoa!! I just got a rather surprising (to me) warning from Gmail. It reads:

You are almost out of space for your Gmail account.
You can view our tips on reducing your email storage or purchase additional storage.

As I said, this was a bit of a surprise to me. When I first began using Gmail, I kept a close eye on my storage usage, but it used to climb so slowly that I soon forgot all about it. But upon seeing the above message, I quickly glanced down to read:

You are currently using 6989 MB (95%) of your 7356 MB.