BlackBerry:
We all know this is the BlackBerry's forte. These little machines from Waterloo rock at email. My BlackBerry delivered email from my various accounts immediately, and notified me with a little blinking red light. Messages are stored for 30 days, and you can perform searches to find that one email from so-and-so or that one vital phone number from two weeks ago. You can also interact with most attachments. Viewing PDFs and other documents works fairly well. I could go on and on. The functionality of the BlackBerry email system is robust, and the number of tasks you can perform are many. BlackBerrys rule the mobile email game. But it ain't pretty. The fonts are terrible, and the general appearance of your inbox is just unpleasant, no matter which way you format it. It looks like lines of code from your Commodore 64. And no HTML emails here. Still, function beats form, and the usability is king. During trade shows or daily jaunts into NYC for meetings, I always remained on top of things. So, big thumbs up for my BlackBerry, it kept me in touch with the world.
iPhone:
The iPhone is an entirely different experience. First, it doesn't deliver emails immediately. You can set it to check as often as every 15 minutes, but that's as close to real-time as you get. Is that a big deal? I suppose not. And of course this drains the battery just a hair faster. It is compatible with most POP3 and IMAP email systems, though I had trouble configuring a couple of my email addresses. My main 'corporate' email account, however, is a Gmail account, and setting that up was a snap. Getting the iPhone to play nicely with full corporate email systems won't be as easy, though it is possible. There are several other issues that prevent the iPhone from being a strong email device.
Speed is number one. The email client is just darned slow. Loading emails is painful. They always snapped right open on my BlackBerry. You can't breeze through emails on the iPhone. Of course, it looks much better on the iPhone. Form beats function here. But that's not necessarily a good thing. The list of woes is long. The client provides only the most basic level of functionality, including replying, forwarding and so on. But you can't download attachments to specific folders. They are viewable in the body of the email only. There is no search capability and you can only store 200 emails on the device, which only goes back a few days for me. I could, however, access the full and basic HTML versions of Gmail through the iPhone's browser, and there I had full functionality and access to every email in my Gmail account. But using it is much slower and somewhat clunky. The same thing applies to Yahoo or AOL accounts. You can still log in via the iPhone's browser and experience more functionality via the Web versions. (My guess is you could also do this for the Web version of Microsoft Outlook, but I haven't tried it.)
There are more deficiencies. With a BlackBerry, you can select a phone number within the body of an email and dial it directly from the email. No so, the iPhone. You can't even select text to cut and paste it anywhere, which you can do on a BlackBerry. The same situation applies to URLs.
There is also no notification light to let you know you have messages. If you have the iPhone set to silent, you will have to unlock it to check for emails.
Conclusion:
So what's the verdict?
Well, the BlackBerry wins hands down at sheer usability, productivity, and speed. While the iPhone is definitely pretty, and let me see my emails and interact with them on a basic level, it simply doesn't match the capabilities of the BlackBerry. I've only used the iPhone for day trips away from the office, and not an extended period. Given the number of emails I receive, I have a funny feeling I'd fall behind after several days out of the office, especially since the limited amount of email storage means I can only go back a few days in my inbox.
Cache aside, for power email users who are used to the high functionality of BlackBerrys, the iPhone is surely going to disappoint.