Verifying my Twitter account: I do not receive the confirmation email

I am attempting to verify my Twitter account. The first step is to verify my email address. When I do this, Twitter say they have sent me a confirmation email, but I do not receive anything. I have tried this now with three different email addresses, and I receive nothing. There is nothing in the spam folder of these three email addresses, either. I have contacted Twitter support several times, but they do not reply. Does anyone know anything about this?