Question about how IMAP works & Outlook 2010

I use Outlook 2010 and just converted from POP3 to IMAP. I had set the send/receive to every 3 minutes. While dragging and dropping my folders into the new account I decided to set it for 1 hour. Then I sent myself an email from my phone and it immediately showed up in Outlook. I moved a message from the online web mail and it immediately moved in outlook.

I know that IMAP is supposed to be immediate with updates to the email client. My question is:

1: If I have outlook set to send/receive every hour, why are the updates immediate?

2: If it is updating by itself right away, why have Outlook do a send/receive at all? IT is such a long slow process with all the folders I have.

Thanks

 

I suspect that Outlook's send/receive setting only applies to POP3. My wife uses Outlook and IMAP and I use Thunderbird and IMAP and in both cases it seems that server communication is continuous, not at set intervals, so new messages appear in the client as soon as they hit the server.

 

After trying to figure this out for a few days and turning off all automatic send/receive, I think what is happening is that the inbox gets updated instantly/automatically. However, I think the sub folders I have created only get updated if I click on them. But I am still not certain. Maybe someone with some knowledge will reply. I have left my settings as never doing a send/receive for the inbox or sent and automatic update for my sub folders once every 4 or 6 hours.