Couldn't you use a rule, like:
Apply this message after it arrives
(clauses to identify e-mails from this sender)
(action on message, like [permanently] delete)
reply using <a specific template>
stop processing more rules
I don't know if the rule will trigger if you have added the sender to
your blocked sender list. You might have to unblock them (remove them
from the blocked sender list) so the rule can catch their e-mails.
Since you are blocking them now, the action clause would probably be
"permanently delete it".
If the sender is using a bogus e-mail address then your replies go into
the bit bucket. If they used a valid domain, your reply gets sent but
they used an invalid or undefined username, so their mail server sends
back a non-delivery status message (and you get blasted again with
"indirect" spam from them). If they specified a bogus domain name, your
mail server will either reject your outbound reply e-mail immediately
(if the mail server checks immediately for that domain) or will later
bounce back your reply e-mail as undeliverable because no such domain
exists (so you get blasted with another message but not directly from
the sender). Or the sender used some other innocents e-mail address and
you blast an innocent with your reply regarding an e-mail they never
sent. So be damn sure you know the sender is using a valid domain, a
valid username, and that they are for THEIR e-mail address. If the
sender used a listserver or other bulk mail utility, you may end up in
an endless loop of replies. They send you their message, you send back
a reply, their listserver returns a reply saying your command was
unknown or it doesn't accept commands, you reply to their reply, they
reply to your reply, and ad nauseum.
I haven't used templates but my guess is to open a new e-mail window,
write the contents of your message but leave the headers empty (To, Cc,
Bcc, Subject), and then use the File -> Save As menu to save that new
e-mail as an .oft template file. You can then select that template in
the reply clause of your rule. I don't see a means of selecting to whom
to send the reply message but since it is a reply then presumably it
goes to whomever is listed in the From or Reply-To headers in the
original message that triggered this rule (i.e., it's a reply so it goes
to the sender of the message). You could easily test the rule by using
a disposable webmail account, like Yahoo or Hotmail, or even by sending
yourself a test message and using identifying clauses that triggered on
your test message, then check if it sent back a reply to wherever you
sent the original test message. Then change the identifying clauses in
the rule to trigger on this nasty sender of yours.
You sure it wouldn't be better to just block this sender as you are now
and play dead? If it is a spammer to whom you send a reply, what you
are really doing is notifying the spammer that the e-mail address they
used is valid AND active and thus making it an even more valuable e-mail
address to them.
