Sorry for the typo; it was not so important and I suppose context was explicit.
"
As you know I think that a front-end program on an MTA can (_not_) be
called an OPES....
"
I will add another important service: mail anonymizing. This is a feature
provided in some mailing list. The problem is that it only anonimizes the
header. If the mail is a reply-to, the name of the replier is often in the
return formula "at 16:24 etc. John Doe etc".
There are many applications, but this feature is for example important in
"dynamic online voting" - wich is probably the only secure simple and cheap
online voting solution I know: the ballots are sent to voters (with a
ballot ID) who reply in anonymous way to the watchdogs mailing list, and
may be to the voters list but without the votes.
The witnessed times of vote and time/ballot ID checking (real time or at
the end) by the voters themsleves prevent tempering. Result is the release
by the watchdogs of the ballots they received which should all be the same.
Everyone has then all the ballots. This method permits to run a vote with
everyone involved being under suspicion (the best is that watchdogs are for
example the candidates - so there is no suspicion of collusion). The only
problem is that a trusted third party introduces the sent ballots ID and
anonymizes the received ballots. Every existing solution will be under
suspicion, and every server related solution may have hidden archives.
Not OPES dedicated services (possibly two: one for inserting IDs, one for
anonymizing) independent from the concerned voting college.
jfc