Your mileage may vary, but for my purposes IMAP offers more benefits and makes managing and maintaining my email accounts simpler.

Exchange or Gmail

Some of the account types offer even more advantages. For example, Exchange and Gmail accounts offer a with some additional benefits. If you have a Gmail account, or a Microsoft Exchange account--like --you can sync in real-time with your email and calendar (and contacts for Exchange).

Using Gmail or Exchange, you can access your entire mail account--including sent messages, and all of your folders and subfolders. So, even if you moved the email from last week with the crucial client data to a different folder called 'Crucial Client Data', you would still be able to access and retrieve it from the iPad as long as you have an Internet connection.

Another advantage of using Exchange or Gmail is that your messages are already scanned for malware, spam, and phishing scams, and those messages are filtered out so you don't have to sift through them in your inbox.