When is retention activated?

(Version 6.6 with newest HF)

I created a archive folder with 120 month retention and a Centera with basic edition behind.

I activated Journaling for 10 Minutes and got an open volume with 104 messages, which stayed in the message center. The volume was still opened.

After that I saw, that I had defined some detail wrong in this folder.

I deleted the corresponding business folder and also the archive folder in the Console. After 10 minutes everything was cleared, in the Console and also in the message center. The messages were not deliverd tot he Centera.

I have the following questions:

• Why it it possible to delete a archive Folder with an active retention ?
• Why we could delete the messages, even if there was a retention?
• When is the retention activated?