Missing the point of "push" email.
Ian Bell writes on Web Worker Daily:
If not knowing I’ve got new mail immediately really makes no difference, I would submit that companies like Movamail and Phoneified, and the developers of some of the other Symbian-based email clients, are all working to produce perfectly capable email clients for mobile devices which fulfill the needs of 99% of the mobile-email-using public.
The problem here is that this completely misses the entire point of push email. Anybody who has had a blackberry for a while, and then switched to something else (say a Treo with IMAP/POP email) understands this.
The problem with push vs. pull email is that pull email requires synchronization of coverage and asking for your email. Or it requires that your phone be polling all the time to see if there is anything new. With pull email, I'm sitting in a restaurant or something and I want to see if I have mail. I pull out my Treo. In the best case scenario, there is good data coverage in the restaurant, and I wait while the mail downloads. In the worst case scenario, the coverage is bad, and I waaaaaiiiitttt for my mail to download, or maybe I just can't get it. By contrast, if I had push email, all message that had come to me in the last 30 minutes or whatever are already on my phone because they came in immediately when I was both in coverage and doing something else (like driving to the restaurant). So with push, there's no waiting, and the messages just show up when I am in coverage, without me having to do anything.
Sure you can set your Treo to poll for mail every 5 minutes. But, you'd better have an unlimited data plan and you'd better enjoy charging your battery a lot.