As government legislation increasingly demands retention of digital correspondence, your email messages, even personal ones, are becoming more permanent every day. Not happy about that? Keep these ideas in mind.

• A simple way to add a base level of security to any email message is by attaching it as a password-protected PDF or Word file. This security is easily breakable, but it’s better than nothing.

• Corporate email servers are likely to remember your email, for better or worse, for years—if not forever. If you don’t want your personal messages on the record for eternity, use a Web-based service like Gmail or Yahoo! Mail instead of a corporate account.

• For even more security, send anonymous email using a free online service like willselfdestruct.com, stealthmessage.com or kicknotes.com. These messages can even be set to delete themselves automatically after they’re read.

• Don’t imagine that instant messaging is more secure than email. Many applications keep logs of IM conversations, and companies can easily monitor IM traffic, too.