Can't access e-mail accounts

[historic]

Hello,

I am a site-owner, and I'm having problems accessing my e-mail accounts. When I try to access the accounts I get an error message that reads as follows:

Internal Server Error
500

User '*****' is over quota.

But according to my C-panel Disk Space usage I still have disk space available. Any help with this?

 

[cPanelMichael]

Hello,

It's possible additional usage associated with your account is found elsewhere on the server. I suggest contacting your web hosting provider for assistance so they can determine what's taking up your account's quota.

Thank you.