The login message for my account says I'm almost out of "space".

How do I tell how much space I'm using, and can I delete something to free up space.

I know my submissions are getting close to the limit, but that's not "space", is it?

Hi, afhiwebmaster.

I believe it is, along with Payment and Secure SSL submissions. There is an option to increase the limit for free when you click on the "Account" button (the icon that looks like a man on the upper right corner):

Just complete any of the options there to increase your limits. If you have already completed all tasks, you can then choose to upgrade. You can also make a copy of your submissions by downloading those in your local machine. Afterwards, delete those on the web to free up space.

I hope this helps.