Today I learn a new trick with magento, You can create multiple customer account using with same email account. This particular trick would be proved time savior and easy to testing customer account, order , newsletter subscription … and testing of all those module where you would required to have different customer and email address.
We need different email address to register different custome to magento. It means  for each customer we need atlease one email account. While we are testing such functionality, its very hectic to open so many email account just for customer registration. Or we need to disturb colleagues to check their email account, whether they got your mail or not,  is there proper content and design is there and so many thing we need to check so many time.
But here I will explain you, how you can register a different customer with same email account.
Just Add a suffix of a plus sign and any combination of words or numbers after your email address.
For Example, if you are already registered with yourname@yourdomain.com which is your real email account.
Now you can register as,

yourname+xyz@yourdomain.com
yourname+123abc@yourdomain.com

Magento would identify as a different customer, but all it email you will receive in you real account that is yourname@yourdomain.com.