Renewal Messages?

I would like to use the membership plugin for my site but was wondering how it handles renewals? Let's say someone pays to be a member on my site. They sign up and I charge them a certain amount for a year long membership. When that year comes to a close, how does your plugin handle renewing the paid membership? Is there a way to alert members that their account is about to expire, prompting them to renew? Is this an auto-renew feature? We need to proactively ask our members to renew in some way - what we don't want is to have to wait until they return to our site, realize their account has expired, and then sign up for another year...if this was the case, we would loose money during the time their account expired and they came back to the site. Does that make sense?