In January 2010, Tumblr introduced the "Ask" feature to its users' blogs, allowing readers to ask a Tumblr user questions -- either anonymously or tied to their own usernames -- and have the answer posted publicly. By enabling the option to let followers ask them questions through an "ask box," Tumblr users can further engage with their readers. Although some users enable the option of anonymous questions, not all do, so you may not be able to ask a question anonymously in all cases.
Go to the blog home page of the person you want to ask, either by clicking on their username in the Dashboard or visiting their URL (username.tumblr.com) directly.
Click the "Ask" link. The location of this link will vary based on the user's blog theme; if you can't find it, you can access this page directly by entering the URL "username.tumblr.com/ask." Not all Tumblr users have the "Ask" feature enabled.
Enter your question or comment in the box, then select "Ask anonymously" and click "Ask." If you don't see the "Ask anonymously" option, the user does not allow anonymous questions.