White list from external file?

[Peter Clark]

We run an in house contacts program, I've exported every email  
address in it to a text file - My intention is to white list every  
individual email, what's the easiest way to do this? Ideally I'd be  
able to point the config to "look" at a text file that contains all  
these emails, and it'll auto white list them all. Failing that, I was  
going to add "whitelist_from" to the beginning of every line and  
append it to the local.cf!
There are over 3000 individual email addresses - if each was added  
individually to the local.cf - huge config! :)

Thanks!
Peter