Thankfully, you can configure when or if messages are deleted from the remote server within the Advanced settings for a POP email account. The options are 'When removed from Inbox', 'Seven Days', and 'Never'--and iOS defaults to 'Never'. The downside to this set up is that every PC or device essentially has its own copy of the messages. If you delete the message on your iPad, it is still there on your PC so you are forced to maintain multiple inboxes.

Another problem for POP accounts on an iPad is that they are limited to a maximum of 200 messages. If you are at a client site and you need critical information that you know is in your email...from last week, odds are good it won't be available any longer on the iPad.

IMAP . With IMAP, the device locally archives messages, but the server is the real message repository. All of your various devices are kept in sync because they are all connecting to the same data on the server. When you delete a message on your iPad, that deletion is reflected on your PC and any other devices set up for that email account.

With IMAP, because the messages are stored on the server rather than on the iPad, there is no 200 message limitation. More importantly, you can load older messages, so you would be able to get that crucial client data from the email last week as long as the message is still in your inbox folder.

A potential downside of IMAP is that you might have the message headers, but not the complete messages, so if you try to open and read your email while the iPad isn't connected to the Internet it may not work. In my experience, though, I was able to open and read the content of my messages just fine without a Wi-Fi connection. The only issue I had was that linked content--like images and such within an email were unable to load.