[14.01.2012 12:06] [Anders Johansson]:
On Friday 13 January 2012 07:32:49 Werner Flamme wrote:
When reading http://en.wikipedia.org/wiki/Blind_carbon_copy, I do not get the impression that is is inteded to have this been solved by the receiving client. However, the text is vague, as are the RFCs.
There are two recipient fields. One that is in the body of the email, and one that is used when talking to the receiving mail server. The first is typically referred to as "header to:" and the second as the "envelope to:".
You're confusing me by by putting together body and header of the mail as body. But OK, as a difference to the envelope, that's clear.
When you send an email, you connect to the receiving mail server, and send the command RCPT TO: followed by all the addresses on that server that is supposed to have the email.
When you put an address in bcc, what this means is that the address is not put into the header, so it is not in the text body of the email. It is in the envelope to: but *only* when sending to that particular address. This means that other recipients of the email don't know it also went to the bcc address. They have no way of knowing about it. The information simply isn't there, so the filtering cannot be up to them.
As I understand this, the (first) server reads the RCPT TO: line and compares it with the to:, cc:, and bcc: lines in the header, since it must know how to forward the mail. Is this correct? And the server eliminates the bcc: line from the mail, since otherways all recipients ware informed about the bcc:, and this is sure no "blind" carbon copy ;-) But what does the next mailserver do? Example: userd@d.com sends a mail to his local mail server (outgoing mail relay) that is addressed TO: usera@a.com, CC: userb@b.com, and BCC: userc@c.com. This first mail server removes the BCC line, and sends the mail with the remaining TO and CC entries to the MX of c.com - this server may not compare the envelope recipient with TO: and CC: - or what? Do the servers compare with Bcc: only? Aaargh, I'm so confused now :-\ Werner -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org