Much like keeping track of who has your credit card number, and who has your snail mail address, one might consider making a database (or spreadsheet) for who has your various e-mail addresses on file.

I decided to make a password-protected database containing the date I register at a website, my username and password, and any other registered info (e-mail address, answer to security question, etc.)

As I use multiple e-mail addresses, I decided to initiate this system in the event I ever let one lapse - then I’ll know who has it and whether I want to go back later and update my profile with a new e-mail address.