When deciding how to access your Google Apps services, our initial recommendation would be to use the Google Apps interface, with access to email, calendars, documents and your websites from a single, easy to use location.   However, if you want to set up a mail client using POP or IMAP with Gmail, we recommend IMAP, and here’s why:

POP (Post Office Protocol) downloads new messages from mail servers onto your computer or mobile device, using programs like MicroSoft Outlook or Mozilla Thunderbird (commonly known as “mail clients”.)  This download method is known as “popping” mail.  One benefit of using POP is that you have access to emails when you are off-line because messages are downloaded and stored locally on your computer or other devices.

However, using POP is not well suited to multiple devices, for instance, at work, at home, or on your mobile phone, since they can get out of sync when new messages are downloaded to one device, but not the other. Things you do on your local device have no effect on the server. You may be frustrated by the fact that any action you take on your device, such as reading, sorting, or deleting, doesn’t sync with your Gmail account.  You may have read and sorted all new mail on your phone, for example, but when you log back in to Gmail using a browser, you see a full inbox of unread messages that must be read and re-organized.

IMAP (Internet Message Access Protocol) provides access to email that remains on the mail server, and a better method to access your mail from multiple devices. If you check your email at work, on your mobile phone, and again at home, IMAP ensures that mail is accessible from any device at any given time, provided you have Internet access.  You are viewing the same email configuration on the server, and actions like reading, storing, or deleting mail happen in real time, regardless of the access device.