You Have Billions of Unique Email Addresses
Email Aliasing with Gmail
Have you ever needed to use a unique email address and encountered the dreaded “This email is already in use” error message? Have you ever developed or tested a software application that requires an email as a username and needed to test multiple accounts but didn’t want to create multiple email addresses? If you have a Gmail account, you no longer need to worry about these issues thanks to a little-known trick called Email Aliasing.
An email alias is simply an email address that is associated with another email address. You send an email to the alias, and the other email address receives it in its inbox. Gmail has this feature built-in using two different methods that automatically create aliases when certain characters are added to existing email addresses.
Method 1: Plus-Addressing
You can add a + and then any valid text string after your username and before the @ sign and it will still go to your email inbox. For debugging purposes, you will commonly find testers using +1, +2, +3 etc. to easily keep track of each account. This can also be easily automated in a programmatic loop to append an index or database record key. Another great use might be to append a role name such as email@example.com or firstname.lastname@example.org .
Note that many email validating regular expressions may find the + sign to be invalid – even though it actually is a valid character for email addresses. If you encounter a site that does not recognize + signs as valid, there is always Method 2.
Method 2: Dot-Addition
Syntax: email@example.com, firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
Gmail does not recognize the period (dot) character in usernames. This means that if your username is “username”, you can sign in using user.name, u.sername, or even u.s.e.r.n.a.m.e and it will still work.
The same goes for emailing. You can email email@example.com and when google receives it, the “.” character will be stripped and the email will be delivered to the inbox of firstname.lastname@example.org . You can add as many dot characters as you would like.