How to Search for Tumblr Users
You can find other Tumblr users on the Tumblr site so that you can connect with them and share posts through your email contact list. Tumblr is a free micro-blogging site that you can use to post messages, pictures, links, music and videos from your computer or your phone. In addition, you can re-post another Tumblr user's posts and you can customize both the theme and color of your Tumblr site.
Log in to your Tumblr account with your user name and password.
Click on the link "Look Up Friend" on your dashboard.
Type your email address user name and password when prompted from Gmail, MSN, Yahoo or Hotmail. Tumblr will search for Tumblr users who are in your email contact list.