A lot has been written about how Google was able to adapt their email engine to support IMAP. It’s use of labels instead of a folder hierachy results in emails never being really deleted even when they are no longer visible in the Inbox folder/label. Essentially, the “Inbox” label is removed, so the email no longer appears in the Inbox. It remains, however, on the mail server.
The quick solution is to just drag emails to the Trash “folder” (really just a special label). This macro automates the process and will automatically move selected emails to the Google [Gmail]/Trash folder, just like deleting normally. Gmail deletes Trash email after 30 days.
Installation instruction are included in the file. As always, use at your own risk.