More Public Information from HCSO
The Harris County Sheriff's Office responded to my email request for "all documents related to the Harris County Sheriff's Office's email retention policy, including emails and other correspondence discussing the policy and changes to the policy [for the time period from January 9, 2008, through January 18, 2008]."
Here are the 24 pages of email they sent me.
The oldest emails are from detectives, with complaints like "this policy change is killing us in Detective unit... I had numerous files that are needed in cases that are currently being worked that were saved in those files" and "I have things I was working on that are gone and I cannot get back or track on what was done."
The newer emails describe how to add personal folders to an email account ("contents of the folder are not deleted by the Department"). The most recent discuss how to retrieve "deleted" email, which is apparently not deleted to Chuck Rosenthal's standards, but rather preserved on tape.
Make of that what you will.