If someone unsubscribes from my list, do I lose that address completely?

All unsubscribed emails are moved to the inactive- unsubscribed list, which you can view at any time. Any email listed in the unsubscribed list will not be sent any messages that you mail out. Welcome Messages

Is it possible for us to personalize an auto response message if we ask subscribers to enter their name and email address?

Yes, you have the option to include mail merge tags in the auto response welcome message based on demographic information that you select and enable.

What is the benefit of a welcome message?

A welcome message is an automatic message that will go out to your users when they sign up for your newsletter through your Opt In Form on your website. The benefit of this is that they instantly receive something in their inbox from your company, and that will help to verify to them that they signed up for your newsletters or updates.