If you are like me and have multiple accounts on Twitter, you are probably aware of the fact that you cannot associate the same email address with multiple Twitter accounts. Try that and Twitter will throw up an error saying - "Email has already been taken".
There’s however a simple workaround that will let you use the same email address with all your Twitter handles - the only condition is that you should be using a Gmail or Google Apps email address.
In Gmail, you can add a dot (.) anywhere in the username and all emails marked to that new address will still reach your own Inbox. For instance, if your original email address is email@example.com, any emails sent to firstname.lastname@example.org or email@example.com will safely reach you as Gmail will automatically ignore the periods in the username.
And that’s what you can use to trick Twitter.
Twitter will consider hello@gmail and he.llo@gmail as two separate and valid email addresses even though they point to the same Gmail Inbox.
When you open an account in Gmail, you automatically get another valid email address that uses the googlemail.com domain.
So if you only have two handles on twitter, you can use the gmail.com address with one handle and the googlemail.com address with the second handle.
Check the Twitter guide for more tricks.