Article 150802 of comp.os.vms:

On Wed, 10 Jul 1996, Aaron Leonard wrote:

> > The DNS can't handle the decision of which "pop.allegheny.edu"
> > server to connect to, because the DNS doesn't know anything
> > about user databases.
> 
> Ken Adelman here came up with a pretty nice suggestion - you could enter
> into the DNS a separate POP server hostname for each user.  E.g.
> if you had POP servers called pop1.allegheny.edu and pop2.allegheny.edu,
> you could have the following:
> 
> brennan.pop.allegheny.edu.      in      cname   pop1.allegheny.edu.
> fred.pop.allegheny.edu.         in      cname   pop2.allegheny.edu.
> ; etc.
> 
   Hmmm.  It's got potential for a small system, but might not scale 
   well for 4-5000 users.  :^)

   I was more curious if anyone knew of something along the lines of 
   a virtual "server" daemon that would do lookups against a CSO 
   database of users - either to interpret the preferred email field
   or to use a pre-defined field for POP.  Then - using that info,
   connect them through ... well, basically what you described in the
   first reply.  I've seen similar daemons for other functions and 
   wondered if anyone had done it with POP.

   andrew.  (brennan@allegheny.edu)