[vidyesh]

First choice is http://mailinator.com/

If its blocked then, these surely do the job

http://10minutemail.com/10MinuteMail/index.html

https://www.guerrillamail.com/

http://www.dispostable.com/

When on tor, tormail.net

[megablast]

Mailinator adds a new host every so often. It shows you the new host as an image, to make it a bit harder for websites to block it.