Mail server add-on for ReadyNAS?

claykin wrote:

When you let a reliable third party operate your SMTP server you offload that responsibility to them. They have trained security people on their staff to keep an eye out for exploits and patches to keep their services safe from hackers. They also know how to keep up with the always moving target called spam filtering. Are most end users going to know how to setup their domain name DNS to make sure they have an SPF record and can pass reverse DNS? Users just need to be made aware of the risks of operating exposed services on common ports.

My ISP already handles spam filtering adequately enough, unfortunately they only offer POP3. What I want is a simple service running on the NAS that will download and upload email from the ISP POP3 server and in return offer an IMAP service that I can connect to both locally and remotely (usually my phone). Yes of course there is a security risk but I think it can be properly managed - I've been running Apache on port 80 on my network for the last 6+ years and I'm confident additional services can be added without the sky falling in. :)