You have a limit of 10 megabytes (10248 kilobytes) of files which can be stored in your home directory, including your public_html directory.

You need to either ftp or telnet to fdt.net and delete enough files to get back under the quota.  You can use the email you received to get an idea of how much you need to delete.  For example, if your email read:

Filesystem   blocks    quota     limit    grace   files  quota     limit
/dev/sdd1     12064*    10248   13356   7days    8    10248  13356

this would mean that you are taking up about 12 megabytes of space, so you would need to delete about 2 megabytes of files to get back under the quota.