How does the e-mail notification in my Web browser work?

Several web browsers have extensions or options that let people know when e-mail is waiting in one or more of their inboxes. Other e-mail notification programs run independently and display a message or icon when e-mail arrives. But how do these programs work?

E-mail notification programs are very similar to the clients commonly used to send and receive e-mail. The difference is that e-mail notification applications are written specifically to check and report whether any new mail is on the server. Some programs allow people to read and even answer their mail, and others simply display a link that connects people to a web mail interface. In general, however, e-mail notification programs don't have the ability to save mail to disk or to organize messages into folders.


Here's how most e-mail notification programs work:

  1. The user configures the program with usernames and passwords from web mail (like Gmail or Yahoo! Mail), Post Office Protocol (POP3) or Internet Message Access Protocol (IMAP) accounts, depending on what the program supports.
  2. When running, the program periodically contacts the server to see if any new mail has arrived. Most programs check the server every few minutes or at the interval the user specifies. They don't typically keep a constant connection to the server.
  3. When new mail arrives, the program lets the user know by displaying a message or changing the shape of its icon.

Different programs have different capabilities -- some allow users to read the message through the notification program, while others simply give the alert that the message is there. Not every program is compatible with every e-mail type -- some support only specific web mail clients, some only check POP3 servers and some support a range of web mail services as well as POP3 and IMAP services.

To learn more about how e-mail and servers work, follow these links: