Several sites maintain directories of email addresses, but they aren’t your best first option. If you know someone well enough, the fastest way to find their email address is usually to just phone them up and ask them. Otherwise, the best place to look is the web site of an organization they are associated with.
While there is no world-wide email directory, there are a number of individual directories that index email addresses, sometimes just for a single company. Some directories collect email addresses by searching the Usenet newsgroups, which is the same way that spammers often get email addresses, so these directories will not pick up addresses of people that use address disguise techniques. Some popular directories are listed below:
- MIT Usenet Addresses Database – Historical, but cool.
Directories generally don’t work well with common names since they return more matches than you can easily search. However, if you are looking for an unusual name they can work very well, since you will only get a few matches that you can scan quickly.
Resources. The FAQ: How to find people’s E-mail addresses provides more information on finding people’s email addresses.