First off, New sysadmin here. I have been using Linux for the desktop for years, but on a server it seems there is a lot I don't know, so if it is simple, please take it easy on me.

I have a VPS running Debian 5 with a mail server (postfix, devecot, clamav, amavis) and a web server (LAMP). Pretty basic stuff, but my VPS frontend is reading 900+MB of memory in use (as is # free). My question is; With a server idling at almost 1GB ram, and a 2GB ram limit, is this going to be a huge issue? My website isn't getting really any traffic right now, but how much traffic is going to push me over my limit?

Clamav and amavis are large RAM users.

But are you sure you're reading it right? You didn't post the output of "free" here. Read http://www.linuxatemyram.com/

I understand the way that Linux handles RAM, however my limit on my VPS 2GB and I have a 6GB Burst. Meaning my VPS sees itself as having 6GB total available RAM, so Linux wont pass off RAM to other applications, it will just keep on cranking up into the "burst" RAM, essentially costing me money.

You're good at the moment with 1GB of ram usage and 5GB free.

I'm never a fan of burst memory on VPS systems. In particular in quantities like you have. Unless the host box has a lot of memory it could only take a few VPS nodes to request another 10GB+ of burst RAM and start killing the box.

Well, the thing is, I don't have 5GB free. I have 1GB free, and 4GB burst. That's my problem, I don't want to push into that 4. I just uninstalled the clamav and got it down to:

You would have still bennett ok Imo. Either way if you didn't clamav it doesn't hurt to remove it.