2 things -
1) You don't need to set up a proper "mail server" in the sense of multiple domains/users and mailboxes. Either sendmail or exim4 can be installed during the build. Those are mail servers, but you really wouldn't need to do much/any configuration. If the only thing you want to have happen is for it to send you syslogs, and not receive mail from the internet, it can do that with super ease. Most of the articles on the web for setting up sendmail or qmail (which I use and love) are great, but also designed for setups of 10-1000+ users, not just a daemon sending out syslogs.
2) Depending on what it is that will be infrequently downloaded, setting up a server at a remote location is probably a big mistake. To download from a remote location, you are going to use up bandwidth at both sides for the transfer. Getting consistent speeds of 1 MB/s is costly, and to transfer several hundred MB files, you can see the problem. The best place for this machine would be in the office the people who need to access the files are in. Nothing crazy, you don't need a mouse, keyboard, or monitor attached. Just plug in the network cable to the network, and the power into the wall. Then folks can connect at 100 MB/s over the LAN cable, giving you literally a hundred times faster connection, and not using any outside (internet) bandwidth. You'd also have the choice of if you want to share the files through a website (apache2) or file sharing (samba/nfs).