Problem: You just told off the CEO in an e-mail and instantly regret it.
Likely Cause: Failure to see that those pay cuts really were for the good of the firm.
The Fix: You may be tempted to use the "recall" command present in some e-mail clients, but don't use it unless you are positive it works and are certain the boss hasn't already read your e-mail. Nothing adds insult to injury more than a reminder of the stupid message you sent, and recall functions often fail in the real world.
If recall isn't an option, walk right into the CEO's office and prepare to eat crow. Resist the urge to apologize via e-mail--it will come off as insincere. If you can't explain in person, the phone makes for a distant second choice. Also helpful: a handwritten apology and a small gift like flowers or tickets to a sporting event.
How to Avoid It Next Time: Self-control is your friend. Check your emotions when using e-mail, and remind yourself how easy it is to begin a flame war, given the impersonal nature of e-mail. Also, make a habit of double-checking message recipients before you click Send to avoid accidentally sending your private rants to the person you're complaining about.
You also have technical solutions. For example, set your e-mail client to delay sending/receiving messages so outgoing mail isn't delivered for a few minutes. In Outlook, click Tools, Options, Mail Setup. Uncheck 'Send immediately when connected' and then click on 'Send/Receive...'. On this screen, change the 'Schedule an automatic send/receive every' option to 10 minutes or so. That should give you enough time to think better of your impromptu hate mail.
Also, if you use Eudora 7.1 for Windows or earlier, consider enabling its MoodWatch feature to help you avoid sending inflammatory messages and messages directed to the wrong people.