Question about letters of rec

1. How do my recommenders send their letters to the school? My guess is that once I start the application, I provide the schools with my recommenders' email address and the school will send instruction. Is this correct?

2. If the school is emailing the instructions to my recommenders, should I provide their work or personnel email? I'm asking this because I work for the government and we have a very strict email filtering system that might block the school emails. But if I provide the schools with personal emails, it might seem less legit.

Thanks in Advance.