hello all
hoping someone might be able to help point me in the right direction.
so, we have a hybrid exchange setup and want to setup a retention policy to delete anything from the 'Deleted Items' folder older than 90 days.
to test, i created a retention tag to delete anything over a day old, added that tag to a test retention policy and assigned it to my mailbox.
when i check in owa i can see a label appear such as:

I've also tested using Start-ManagedFolderAssistant -Identity "xxx" to force the ManagedFolderAssistgant to process the retention policy on the Deleted Items folder.
This is where my lack of knowledge shows and what i need help with. When i run the above powershell i can see the label above appear on any email in deleted items folder that HASN'T previously been processed.
What I don't know is what actually does the removal of email? is it the same ManagedFolderAssistgant that not only applies the retention policy but also goes through and says to an email i see you have gone past the date/time in your applied retention policy so i am going to remove you from the folder or is there a separate exchange process that does the actual email removal?
also, is it a live process that as soon as the date/time is reached the email is removed, or is it a process that runs say once a week and goes through the mailbox?
hope it makes sense and thanks