Review: Samsung Infuse 4G
Nothing sets the Infuse apart in the messaging department; it mirrors the experience that most Android handsets provide.
The SMS application remains simple yet powerful. Messages are threaded in a conversation style, and media (photos, video, audio) fall inline with the text. The usual two Android email applications are also present. There's the generic email app for POP3/IMAP4 and Exchange, as well as the native Gmail application.
On the instant messaging side of the equation, the stock GTalk application is on board for Google users, but a catch-all application for other services is missing. If you want to chat via AIM, Yahoo, or Windows Live, you'll need to seek out a third-party solution from the Android Market.
The Infuse also has a home screen widget for accessing generic feeds, such as Twitter, Facebook, and so on. The feed works well, but I found it to be a bit limiting and not nearly as feature-rich as the full-fledged social networking applications themselves.
Facebook and Twitter aren't pre-installed, so you'll have to download them yourself.