There are several ways to find out the email addresses of people using your computer. Suppose you have an email account in Yahoo.com or Hotmail.com, whenever you login into your account, temporary information about it is saved in your computer. If someone is also checking his/her email on your computer, his information is also temporarily saved in your computer. Even if you type the starting alphabet of his/her email id, it will automatically show his/her user id.
If you are using MS-outlook, you will have to go to the 'Tools' option on the menu bar and then select email accounts. Here you will the information of other email ids in your computer.
If you are using Outlook Express, select the 'Tools' option from the menu bar and then go ahead and click on accounts. Here you will get complete information of all the email-ids that are accessed from your computer.
If you are using MS-outlook, you will have to go to the 'Tools' option on the menu bar and then select email accounts. Here you will the information of other email ids in your computer.
If you are using Outlook Express, select the 'Tools' option from the menu bar and then go ahead and click on accounts. Here you will get complete information of all the email-ids that are accessed from your computer.
