Ofaco for Mac acts as a text completion plug-in for the Mac Mail app, replacing the default system dictionary that has long word lists, which make it hard for you to find word alternatives quickly. It integrates well with the Mail app and makes it a little easier and quicker to compose e-mails. You will want to check it out.
Ofaco for Mac installs as a plug-in for the Mac Mail app, so to use it you have to open your Mac app and begin composing a new message. It basically replaces the slow and unwieldy default dictionary-based completion mechanism of the Mail app with a faster, more convenient one that uses words from the message window you're typing in. The words offered are consistent with your e-mail and easy to find and select. A nice feature of the app is that it lets you add your own words and phrases to the list of completions. This application doesn't take up much space, and most of all, doesn't slow down the Mail application or create any other performance issues, which is nice.
Ofaco for Mac won't disappoint you. It's a tiny but useful plug-in that will improve your Mail app experience, helping you get rid of those lengthy word lists that the default mail dictionary offers. If you use your Mail app a lot and want a nice text-completion plug-in, you should definitely grab this one.
Mail, like almost all Cocoa applications on Mac OS X, offers text completion, which can be invoked by hitting either F5 or Esc. When it was introduced, it offered completions based on the list of words from the mail you were typing. Unfortunately, somewhen Apple decided that it would be smart to use the system dictionary for completion. From that day on, using the completion in Mail.app meant to have to scroll through an endless list of words to finally get to the one you wanted. In other words: it slowed typing down instead of making it faster. And it was (and is) absolutely useless when writing in a language that's not your system language.
Enter Ofaco. The name "Ofaco" stands for "Old-fashioned completion", which says it all: it's a plugin for Mail.app that replaces Mail's dictionary-based completion mechanism with one that uses the words from the message window from which it was invoked. Additionally, I added a way to define default completions that will always be added to the completion list (and which, by the way, can not only contain words, but also phrases).