I'm a heavy e-mailer on my iPhone, and one of the things that really bugs me about the built-in mail client is that it falls just short of being ready for business use. For instance, it lacks the option to flag messages, have different signatures for different accounts, or simply turn on and off an out-of-office auto-responder. But what really irks me on a daily basis is the search tool that got added in OS 3.0. Don't get me wrong, this was a really important thing to add--but there's a big problem with it: it's limited to the subject line and who the sender or recipient was.
That level of search is certainly a good start, but it doesn't compare to newly-released app ReMail (download), which can index an entire e-mail account and do full-text search within all your messages. You want to find a word or phrase in an e-mail body? It can do that, and it's fast. Better yet, it doubles as its own e-mail app, so you can open up and read messages; copy parts to stick in new messages; or forward, reply, and delete--all without leaving the interface.
Of course having the same account in both ReMail and the mail app means that it takes some extra storage on your phone, but what's surprising is how little it uses. A 140MB Gmail in-box I sucked in for my test account squeezed down to just 25MB. It works like that for one main reason--the app doesn't download attachments until you open them. Though the nice thing is that after it's been opened, it stays cached on the device so you can open it again.
Former Gmail engineer Gabor Cselle, who makes the app, is pushing ReMail as a tool for commuters. One thing that makes ReMail especially well-suited for that is that you can access your entire in-box--even offline. That's compared to the iPhone's built-in Mail app, which has to hit the servers to continue a search if what you're looking for falls outside of what it has recently saved on the device. This can also be a boon when traveling internationally, since you can access and search your account without being connected to, or having to sync up with any servers.
As fantastic as the app is, there are a few annoying bits that will keep it from fully replacing the Mail app, including the fact that it's currently limited to one account at a time. You can go in and switch it with another account, but then your old index gets deleted. Another pain point is that it doesn't work with Microsoft Exchange, just Gmail and IMAP. That's fine for casual users, but business users won't be able to get all that full-text search goodness on their work accounts, which for me, would have been one of the big draws. Cselle told me that Exchange and other account types, like POP, would be added later down the line, but for now he just wanted to get it out there.
Other small annoyances include no landscape view, and a slider you have to toggle every time you want to copy text from a message. I didn't mind this at first, but it's a real drag when you realize you want to copy something halfway down a message and have to go all the way back up to the top to turn that mode on.
For $4.99, this is a very, very solid way to search through e-mail. Though like many other innovative applications that have come along to try to improve on what Apple's done, it runs the risk of being made obsolete by the very product it's trying to fix. I wouldn't put it past Apple to have full-text e-mail search as part of its next major OS update--if not sooner, considering it's already such a big part of its desktop application counterpart. Though if you're willing to invest in this app in the meantime, you'll never have to trudge through e-mails again.
The good:
Fast, highly-customizable search
Autocompletion of search terms
Saved search terms
Built-in e-mail functions that let you create news messages right inside the app
Local cache of data for offline reading
The bad:
Limited support for e-mail services
Possible obsolescence by an Apple software update
No landscape view
Copy and paste toggle is clunky
Can take a very long time to do the first in-box download, and you have to leave the app running while it's happening
App can crash when doing long downloads or when opening up attachments