Do you want to use single Gmail account as different Gmail accounts...

Consider a test case where you have to create 100 users with different emails in web app and app gives validation error when trying to save different user with email that is already assigned to another user.

Then what is the solution?
Will you create 100 Gmail accounts?

The answer is 'No' and it hassles. Here is a SMART solution.

Say you have one Gmail account 'you@gmail.com'

Solution is 'you+{Random text}@gmail.com'.
You can use this format for as many times as you can.

Let's see one example for this test case:
1. Create one user with your email 'you@gmail.com'
2. Create 2nd user with email 'you+001@gmail.com'. Yes, 2nd user to is created

So you can create 100 user in this way using emails 'you+001@gmail.com', 'you+002@gmail.com', 'you+003@gmail.com'........'you+100@gmail.com'.....continues.

Now try this:
Send an email to your gmail account 'you+001@gmail.com' using this format and the email will be sent to your Gmail accout 'you@gmail.com'.

If you reply to this mail reply mail will be sent from 'you@gmail.com' not from 'you+001@gmail.com'.

Hope this post is helpful to you....

-Satish