--On Friday, 08 July, 2005 04:27 -0400 "Robert A. Rosenberg"
<hal9001(_at_)panix(_dot_)com> wrote:
At 06:04 +0200 on 07/08/2005, Frank Ellermann wrote about Re:
OPES and Email:
What's wrong
with RCPT TO;<paul> and To: <sandra> ? Maybe Paul was in a
Bcc:, that's nobody's business but his.
There is nothing wrong with the RCPT TO:<paul> [triggered by a
BCC:<paul>] so long as there is also a RCPT TO:<sandra>. There
is also the case where the message is a Mailing List (or
.forward or alias triggered forward) fan-out where all of the
RCPT TO command entries will have no corresponding To or Cc
headers.
There is also the following case, which is _extremely_ common
and basically required...
To: tom(_at_)domain1, dick(_at_)domain1, harry(_at_)domain2,
sandra(_at_)domain3
In general, when this arrives at "domain2", there will only be
RCPT TO:<harry(_at_)domain2>
similarly, when it arrives at domain1, there will only be
RCPT TO:<tom(_at_)domain1>
RCPT TO:<dick(_at_)domain2>
In general, only the originating MUA and the MSA sees the full
list of RCPT commands. If either domain1 or domain2 see those
not bound for them in the cases above, we get (depending on how
those servers are configured) duplicate messages, mail loops, or
claims about invalid relaying.
john