Number of transactional emails sent or left

Where can I see how many transactional emails I have left per day? It looks like the standard includes 300 a day. What happens when you reach that? Do emails delay until the next day? Do you get a warning email? Thank you.

This is visible here:

When limit is reached:
This article of our help center gives more details:

If you hit the daily limit, you will be able to manually send your email to all your contacts on the next days thanks to the Requeue feature. You can also upgrade your plan to remove this daily sending limit.

And about the limit: for monthly limits we send the email when you are about to reach the limit.
If you have a free plan, you get the notification when you reach 100% of the quota

This is helpful information.