That is not possible with outlook and IMAP accounts
the only thing you can do to "speed up" the process is to configure automatic purging (automatic purging only works when you are online)
Click a folder in your IMAP e-mail account.
On the Edit menu, point to Purge Deleted Messages.
Click Purge Options.
The Internet E-mail Settings dialog box opens.
On the General tab, under Purge Options, select the Purge items when switching folders while online check box.
So when you mark a message for deletion and you click on any other folder all the messages you marked for deletion will be deleted from that folder (if you are online)
