In message <BE671C91DB4DF247BD6753000BEF8A1F6F56@morpheus> you write:

|> Question1: Will Netbsd work on this system?

AFAIK yes, but since it probably only has 4M of RAM, you might get
better bang-for-the-buck if you don't run a full-blown Unixoid OS
on it but get some Xkernel distribution instead. These consist of
a severely stripped down kernel, a shell, a shell script replacing
init(8), an X server, and very little more. AFAIK there are at
least two different ones floating around, one based on SunOS-4.1.1
and one base on some NetBSD. I used the SunOS based one on some
3/80's for a time and found it quite useable.

|> Question2: Can I remote boot it by running a tftp server on an MS
|> machine?

You need rarpd, rpc.bootparamd, tftpd, and full NFS service.

|> Question3: Will it be powerful enough to run X, as well as working as a
|> basic Sendmail/Pop3 server for 3 users

Either X or mail, not both. Besides, considering the amount of
malware propagating itself by mail, I'd use something more recent
running Solaris and sendmail-8.11.6 or -8.12.1 with attached virus
scanner.

|> (I don't know how much RAM is in this thing,

Shipped from Sun with 4M, there were some (officially unsupported)
third party upgrades to 8M or even 12M.

|> but is processor speed an issue assuming there's enough RAM)?

To a degree. Don't expect wonders from a 16MHz 68020 impeded by a
cycle-stealing frame buffer.