This section will show how to guess corporate and academic accounts. Many companies have their email receiving system set up so that if it doesn't recognize an email address, it hunts around until it finds an address that is close. If your correspondent is likely to get his or her email through work, first figure out what the domain name is by making a few guesses and searching for a Web page with that domain name. Even if your message doesn't reach Aunt Mabel, you may get an automated response with more information. The response might tell you what Aunt Mabel's address is, or it might explain how to figure it out.
Many companies have a policy on how they assign addresses.
Bigger companies are more likely to require that all email addresses follow one of the above schemes. However, the bigger a company, the more likely that extra characters may be inserted in order to make the address unique. If Aunt Mabel is a student, teacher, or staff member at a university, you may be in luck. Most universities have some sort of email directory. For example, see the University of Illinois' online phone book.