What is POP and IMAP? POP and IMAP is what allows you to download messages from Gmail's servers onto your computer so you can access your mail with a program like Microsoft Outlook or Thunderbird, even when you aren't connected to the Internet. How much does POP and IMAP cost? POP and IMAP access are free for all Gmail users. What’s the difference between POP and IMAP? If you’re trying to decide between using POP and IMAP, we encourage you to use IMAP. Unlike POP, IMAP offers two-way communication between your web Gmail and your email client. This means when you log in to Gmail using a web browser, actions you perform on email clients and mobile devices (ex: putting mail in a 'work' folder) will instantly and automatically appear in Gmail (ex: it will already have a 'work' label on th...