One fewer reason to store data on your computer
That includes your email. Web-based email is popular, but what if (like me) you prefer to do your email through an email program (like Outlook Express or Thunderbird) than through a Web browser? Up to now you’ve usually had to download your email to your local computer, while (optionally) leaving your original copies on the server. While that works, unfortunately the communication goes only one way: when you read an email message through your email program it gets marked as “read” locally, but not on the server. Same for deleting messages and other things. And properly organizing the messages you send is usually a hassle.
There is a solution: it’s called IMAP (Internet Message Access Protocol) and is one way that an email program and a mail server can communicate. With IMAP everything is synchronized: whatever happens at one end gets reflected on the other. And the mail server is the “primary residence” of your email; you may have copies of various messages locally, for speed and for availability when you have no Internet connection, but IMAP meets my objective of storing your data on servers intended for that purpose.
IMAP isn’t new; in fact it’s older than the public Internet. But the popular free email services such as Hotmail and Yahoo! Mail and Gmail haven’t supported it, unfortunately.
This has now changed. Gmail has just added IMAP access as a new feature (though Google says it will take a few days to be rolled out to all Gmail users).
Since Gmail is so popular, its addition of IMAP means that a lot more people will no longer have any good reason to store their data on their local computer. The effect will be magnified if Gmail's competitors try to keep up by also adding IMAP.