Stebbens wrote:
The problem is a result of the lack of standard formatting guidelines
for outgoing Bcc: email. Procmail most typically processes incoming
email at a destination site; the BCC formatting (or lack of it) is done
on outgoing email, at the originating site.
For this discussion, let's make distinctions as to the kinds of mail
there are: (a) incoming mail, and (b) outgoing mail. Bcc's are inserted
into outgoing mail by the user, and the message is then handed to a MUA.
The MUA may then handle the BCC's or defer that to the Mail Transport
Agent (MTA), such as sendmail. Whichever agent performs the Bcc
function, that function is performed in at least three different ways:
1. Many MUAs format outgoing mail without the Bcc: headers, so that the
same message header can be sent to all recipients. The Bcc:
recipients receive an extra line in the message body, indicating the
nature of the mail. The text of the message varies from MUA to MUA;
The Rand Mailer, MH, for example inserts the lines around the
original text:
------- Blind-Carbon-Copy
...
------- End of Blind-Carbon-Copy
2. Some MUAs will send the message, separately, to each Bcc: recipient,
with the recipient address on the Bcc: header. Each Bcc recipient
thus knows that they received the message by way of the Bcc, but do
not know whom else was a Bcc recipient. All Bcc recipients are
private, even to other Bcc recipients. (It would be nice if all MUAs
behaved this way).
3. A few MUAs deliver the message without the Bcc:, but also without any
special indication; you must guess that it was a Bcc.
The original email standard RFC822 says this about Bcc:
4.5.3. BCC / RESENT-BCC
This field contains the identity of additional recipients of
the message. The contents of this field are not included in
copies of the message sent to the primary and secondary reci-
pients. Some systems may choose to include the text of the
"Bcc" field only in the author(s)'s copy, while others may
also include it in the text sent to all those indicated in the
"Bcc" list.
So, procmail *would* handle Bcc's correctly if the sender's MUA included
the Bcc in the header in the first place. But, since procmail is most
typically used on *incoming* email, it will never have a chance to deal
with Bcc: headers.
'Nuff said?
Alan Stebbens <aks(_at_)sgi(_dot_)com> http://reality.sgi.com/aks
----------------------------
Alan,
Originally, I thought... Ya, enough said. So I spoke to my ISP to see if
there was any way they could adopt your #2 approach above. They have not
answered me yet, but something occured to me....
There MUST be some trace of the BCC destination that travels with the
e-mail. Otherwise, how does it know its destination? If I'm right, then
couldn't procmail use this to properly handle the message?
Surely other procmail users must somehow be handling BCC's. Otherwise,
there are alot of BCC messages falling through to the procmail sysops.
Seems ironic that the private messages are the only ones that get misdirected.
This is a GAPING hole. I can't be the only one to have this difficulty -am I?
Mark Nightingale