downloadsquad.com —
"Why is IMAP integration a good thing for Gmail? POP was a stepping stone, but IMAP pushes Gmails benefits over the top. With IMAP, users can now access their email via a desktop application like Outlook or Thunderbird, read emails, make changes, delete, and have the changes made across platforms. So if you now log into your Gmail account, the message which you read in Thunderbird, will now be marked accordingly. No more wasting time trying to sift through emails that had already been answered."
"Take a peek under your Settings in Gmail, and click into your 'Forwarding and POP IMAP' tab to see if you are one of the lucky ones who got IMAP first."