Rackspace is a legitimate cloud computing company, however, some cyber criminals proliferate a spam email campaign using an identical name (so, the scam is also called 'Rackspace'). Scroll down to the IMAP Access section and select Enable IMAP. On the Settings screen, click Forwarding and POP/IMAP. Click the Settings button in the upper, right corner of the window and select Settings from the drop-down menu. To setup your Gmail account to use IMAP, sign in to your Gmail account and go to Mail.
Frequently Asked Questions What are gmail imap settings?