[cobalt-users] EXCESSIVE VIOLATIONS WARNING

["Jolley, Carl" <Carl.Jolley@xxxxxxx>]

One of my site-adm's recent got an e-mail, portportedly
from himself with the above subject listing a host name.
The body of the message says:

This user from this domain tried to hack into this page at....

then it gave a date and time. I looked in the error log
for the web server and all I saw was 4 attempts to request
a directory index of the web directory of the web site. I had
previously disabled all attempts to get directory indexes
from this box but my impression is that lots of search engines
probably had been receiving errors when trying to get directory
indexes but I had never seen this error before.

My questions are: what generates such an e-mail and under
what circumstances and should I consider this a serious
hacking attempt or just a fluke occurance?