If you use POP in ALL of your accounts, you can set this up in Account Settings. In each account, go to its settings. Under Server Settings, there is an Advanced button where you can select where the incoming messages go to. I'd suggest you choose "Inbox for a different account" and then "Global Inbox". Note this will only affect messages that arrive after you make this change, leaving previous messages in their original Inboxes. If you don't use POP, but IMAP instead, you can try '''View|Folders |Unified''', which presents messages as if they were all in the same Inbox. It does the same for your Sent, Trash, Junk and Drafts folders. Another approach is just to write a filter in each account that moves all incoming messages to a chosen Inbox or other folder. A disadvantage of this is that subsequent filtering won't run automatically, since filters only run automatically for incoming messages as they appear in the Inbox, and not in other folders. Personally, I'm happy to use '''View|Folders|Unread''', then I am shown all the folders containing unread messages, regardless of their location. So this can find messages that were moved automatically by filters.