Bulk removal of unrequired SMTP addresses in AD

Hi,

I have a task to complete where I have been given a list of email
addresses that are either set to primary or secondary email addresses
within AD.

There are over 500 users to go through and I wondered if there was an
automated way of removing these without having to open the account -
change the primary (if required) and remove the requested email
address.

Any help would be welcomed! As if I start this task my fingers are
going to be worn down to the nub :)

Cheers!
Sam
.