Exchange 2003 -- Mailbox Management not deleting ALL messages aged 30 days or older...

I've recently created a Mailbox Management task within Exchange 2003 that, every night, looks at the contents of the Deleted Items within a particular mailbox and deletes mail that's 30 days or older.

The scheduled task ran on its own last night and I have confirmed that messages within the right mailbox and the right folder were, in fact, processed. Many mails were deleted ... but not never email older than 30 days. In fact, the choice seems kinda random.

Last night 3/10/2010 was the 30 day watermark. Mails were deleted from 3/10/2010, sure enough, but not all of them. Mails older than 3/10/2010 were deleted as well, but, again, not all of them.

The only criteria I have on the management -- aside from the single mailbox and single folder scopes -- is the age criteria. The size criteria is set to Any, meaning I don't care about the size. I care about the age.

It's made me wonder where there is some sort of limit on how many mails can be processed?

The schedule is set for 12am and 1am every night.

Any hints appreciated.

EDIT: Here are pics.

And here's an example of one of the reports:

    The Microsoft Exchange Server Mailbox Manager has completed processing mailboxes
Started at: 2010-04-10 22:52:01
Completed at:   2010-04-10 22:52:10
Mailboxes processed:    1
Messages moved: 0
Size of moved messages: 0.00 KB
Deleted messages:   114
Size of deleted messages:   4.41 MB

That report up there is from a MANUAL run of the Mailbox Management Process. If I run it again I get another report stating that nothing was deleted.

From serverfault tcv

• 1. Do you have it set to only delete mail that's been backed up? If so, is your back doing a full backup on a regular basis?

  2. How long do you let it run, and how large is/are your database(s)? If you only let it run for 30 min and you have a 50GB database, that's not going to cut it. I've got around 25GB and it takes about 4 hours to do all the maintenance (not exactly the newest server either).

  tcv : I am not sure where I would set it to delete mail that's already been backed up. That doesn't seem like an option in the dialogues I've seen. As to No. 2: The schedule is set to start at 12am and stop at 1am. I have the task set to send a report to me. In that time, I got 4 reports, all processing that one mailbox and only the FIRST report showed any actual deletes. So, I am little lost on how to answer your question.

  tcv : Oh, my database is 30gb. But it seemed like the Management process ran for so many minutes, stopped, sent me report, then ran again, stopped, sent me a report and repeated about four times until 1am. I am scoping this down to 1 mailbox.
  From Chris S

• I found the answer here: http://msexchangeteam.com/archive/2004/08/17/215807.aspx

  This led me to this MSKB Article: http://support.microsoft.com/?id=326397

  "3" is the behavior I want. I set it and KABLAMMO all the mails I wanted gone are gone.

  From tcv