All server stored mailboxes with an IMAP account are kept synchronized with the server automatically with each email client used to access the account. Send a message with the iPad's Mail application and the sent message will be available in the account's Sent mailbox with the email client used on your computer for accessing the account, with a device such as the iPhone, and via webmail access for the account using a browser, which is the same when sending a message with any email client used to access the account or when sending via webmail access using a browser.
This is not available with a POP account. Although it is possible to access a POP account with more than one email client, a POP account is designed to be accessed with a single email client only. An IMAP account is specifically designed to be accessed with more than one email client.
Email account mailboxes and messages are not included with the iPad's backup that is update by iTunes as the first step during the sync process, and email account mailboxes and messages are not synced via the iTunes sync process. If you need or want to restore your iPad with iTunes, any mailboxes created and stored locally on the iPad if this were possible would be lost. Not so with an IMAP account since all messages in server stored mailboxes are stored on the server.
I understand. I have this free POP account from earthlink, my ISP. So, I'm stuck with POP, which has never been a problem until I got the IPad, and it's not a biggie. Again, if you move the message to a Keynote document, it will be synced with the computer.
