My company just started sending out newsletters to our customers but we have a few thousand that we have no email address. Looking for a service that will get these for us.

I’m trying to set up a list of names/email addresses that I can just click a button and a bunch of email addresses show up to send email. I keep trying to add categories but it won’t let me. Basically I would like to hit compose insert a bunch of email addresses with one click and start my message. Is this possible? I would like different lists for different types of emails, for instance a forwards list, business list, party list, family list, etc. Thanks for you help!