Doesn't change the fact that this preferred form of communication by no means guarantees delivery in a certain timeframe. It's not a google problem. The email can be "stuck" in every place between you and the recipients mailbox.
to highlight this, I can think of an emails that got delivered YEARS after I hit send. This happened once in almost 20 years of emailing, yet in still happened. This probably occurred about 6 years ago.
