Gmail Question

I’ve been forwarding my email to gmail for the past couple
years to have a backup in case my mail server goes down. It’s come in handy a
couple times and with 2.5gbs of mail storage, it was a great free backup
solution.

But all buckets get filled up at some point and last month,
I hit the 2.5gb limit and people who sent me mail started getting bounce
messages from gmail. I was still getting
the mail but they didn’t know that. So it was confusing and not good.

I went into gmail and deleted a bunch of old mail, got my
mailbox down to about 96% full and the bounces went away.

But I hit the limit again earlier this week and the bounces
started again.

I went back to gmail and deleted some more old mail. 

But this stopgap solution is bothering me.

I’d like to delete all the mail in the box and start over
again.

Does anyone know how to do that?