Problem: Email is usually used as login username. There are times when you want to test a system by using several email accounts. And you usually need a lot more than the number of your existing email accounts. Now you think of opening another account from email providers.
Solution: With gmail, you can have only one account and use it with different addresses.
Here's how:
Assuming your email is myemail@gmail.com
Emails sent to the following:
myemail+001@gmail.com
myemail+002@gmail.com
myemail+003@gmail.com
myemail+010@gmail.com
... and so on
will be all sent to myemail@gmail.com.
Got the point?
Enjoy testing...