Thats how IMAP works and is exactly why I use it.
What is the basic difference between IMAP and POP3?
IMAP can be thought of as "remote" e-mail storage, while POP3 can be thought of as a "store-and-forward" service. Ultimately they both accomplish similar tasks, but often one will suit your needs better than the other.
What are the Benefits of IMAP?
Since you can view just the header information without downloading the entire message, you can delete large messages without wasting time for downloading them. Also, because the messages remain on the server, you can access your mail from multiple locations at the same time and ensure that your messages are always available for you. And, since the messages remain on the server, if your computer crashes you don't have to worry about losing your messages. IMAP is generally faster and more reliable, especially with certain email clients such as Microsoft Outlook.
What are the Benefits of POP3?
Since all of your messages are downloaded immediately, after you check your mail at your computer, you do not need to actually be connected to the Internet to read your email. Also, because the messages are downloaded to your computer you do not need to worry about accruing disk usage charges because the messages do not stay on the servers. Just make sure your email client is set to delete email messages from the server after downloading them, or else all your emails will sit there, taking up space, until you use Webmail or an IMAP client to delete them!
What are the Drawbacks to IMAP?
There are few. Unlike POP3, IMAP requires continual access to the server during the time that you are working with your mail.* Also, because the messages are stored on the server, it becomes much easier to go over your disk quota on our oldest servers. And like any new service, there is a slight learning curve to get used to IMAP since most people are used to using POP3.
*Note: Some email clients have an Offline mode which can negate this drawback, effectively keeping a local copy of your email as well as the copy on the server. Please consult your mail client vendor for how to configure this feature if available to you.
What are the Drawbacks to POP3?
The major drawback to POP3 is that it is an older protocol that was designed before people were able to easily send large emails with attachments. Because POP3 downloads all the mail on the server at once, people are occasionally unable to successfully receive their messages because POP3 will get stuck or disconnect when trying to download large messages. To fix this, people will either need to contact tech support or log onto our webmail system to delete the large messages themselves. Also, if you use POP3 and are traveling or check your mail from multiple locations, you will not be able to view any of your old mail because the messages only exist on the computer on which you originally received your mail. Finally, some email clients, such as Outlook, are more prone to certain bugs (such as downloading duplicates of emails) when using POP3 than IMAP.