I don't have the grouped boxes but I use a sieve filter on my ISPs mailserver to automatically create folders based on [email protected]

Here is my script:

require ["fileinto","imap4flags","variables","regex","mailbox"];

## A catch all filter designed to automatically organise emails sent to a catch-all address into a folder based on the receiving address e.g [email protected] --> INBOX.Amazon ## If the folder doesn't exist it is automatically created

if exists "X-Delivered-To" { if header :regex "X-Delivered-To" "([^@]+)" { set :upperfirst "prefix" "${1}"; fileinto :create "INBOX.${prefix}"; stop; } }