Last week, Google introduced offline email with Gmail that’s IMAP and Outlook independent.

This is a huge step forward, as one of the main reasons why I still use Microsoft Outlook is the ability to “store and forward” email and work offline. Those 5 hour cross country flights or half hour waits at the coffee shop can be put to better use while staying in touch with clients.

The current setup for my Ultimate Email System consist of Google Apps, Gmail IMAP, Outlook, and Blackberry.

The first thing I want to check out are the security features. How are the files stored? As plain text files in your browser’s cache? At least with Outlook, you can password protect your PST. Same with an Enterprise user Blackberry; you can send a remote wipe in case you lose it (and we all know how often that happens!)

At the time of their press release (or blog posting), offline Gmail is available to everyone who uses Gmail in US or UK English.

Here is a snippet:

Once you turn on this feature, Gmail uses Gears to download a local cache of your mail. As long as you’re connected to the network, that cache is synchronized with Gmail’s servers. When you lose your connection, Gmail automatically switches to offline mode, and uses the data stored on your computer’s hard drive instead of the information sent across the network.

You can read messages, star and label them, and do all of the things you’re used to doing while reading your webmail online. Any messages you send while offline will be placed in your outbox and automatically sent the next time Gmail detects a connection.

And if you’re on an unreliable or slow connection (like when you’re “borrowing” your neighbor’s wireless), you can choose to use “flaky connection mode,” which is somewhere in between: it uses the local cache as if you were disconnected, but still synchronizes your mail with the server in the background.

Our goal is to provide nearly the same browser-based Gmail experience whether you’re using the data cached on your computer or talking directly to the server.