[14.01.2012 13:24] [Anders Johansson]:
On Saturday 14 January 2012 12:59:10 Werner Flamme wrote:
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?
To make it clearer, let me give you an example:
Thank you, Anders!
a mail is addressed to a@foo.com and b@foo.com, cc c@bar.com and bcc: d@baz.com
The client connects to the MX for foo.com and sends in the envelope
RCPT TO: a@foo.com, b@foo.com
the contents of the email are To: and CC: only, not bcc. it then connects to the MX for bar.com and sends
RCPT TO: c@bar.com
and finally to the MX for baz.com and sends
RCPT TO: d@baz.com
The actual email contents are the same in all three cases, To: and CC: only, no bcc info. The only server that sees that d@baz.com gets the email is the MX for baz.com. foo@com and bar@com know nothing about this.
I understand your example. But... in most companies, your client will not connect to MXes directly. Instead, you use your company's mail relay server (maybe someone wants to add this nonsense "confidential" footer, or the firewall simply does not allow direct mailing) and the relay server contacts the MXes. Ah, brain is back (I hope)! Of course your client sends all those recipient addresses to the relay server, the relay "bundles" them and connects to the appropriate MXes. Is this correct?
Your client will then note that you are nowhere in To or cc, and deduce that you must have been in bcc, so e.g. kmail will then display your address as bcc. but this is a client side nicety. it is not in the actual email itself.
Yes, and Thunderbird (at least at some version) displays all the recipients, and you might have a guess now, why you are reading the mail, since you were not in the recipient list :-) And when there is no recipient in the mail at all (because some braindead sender only used bcc), you get "undisclosed-recipients;" shown in TB.
instead, and the mail administrator of foo.com would have been able to see d as a bcc recipient (since all is logged), but a and b when looking at their emails in their inboxes would still only have seen the actual mail contents, which as I said were always limited to To: and CC:
Yes, the admin, human brain and so on... Do you know any mail admin, who has even got the time to look at this? ;-) I hope I am halfway back with my brains now. Phew, it took a while :-\ Cheers, Werner -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org