[pmmail-list] [mkc] bcc: Inconvenience

[Tim Roberts]

On Wed, 27 Aug 2003 18:44:34 -0400, Steve Marvin wrote:
>
>Not all of this is correct. The SMTP server does not look inside the message
>data (should not - I don't know ALL possible SMTP servers) and delete lines.

Actually, sendmail and its kin DO have to manipulate some of the headers.  
They will add quite a number of headers, might possibly rewrite the address 
headers, and might rewrite the Date: header as well.

>The way PMMail works is that To: Cc: and Bcc: are placed inside the message
>body in the outbox, but when sending the DATA to the SMTP server the Bcc:
>header is suppressed.
>
>If you actually send a message with Bcc: header(s) in the message data, it
>will arrive at the destination with them still there (can't do this with
>PMMail because it strips that header).
>
>Prove it to yourself by drafting a message with Bcc: and run a packet
>sniffer or use OS/2's IPTrace while sending it to the server.

I started to compose a reply saying exactly the same thing.  Before I did so, 
however, I wanted to PROVE it to myself to avoid increasing my "bozo 
quotient".  So, I telnetted into our e-mail server's SMTP port and did the 
experiment, typing SMTP directly in to the server with no middleman.  To my 
rather great surprise, sendmail stripped the "Bcc:" header out of the message 
before sending it back to me.  I grepped through the sendmail.cf file looking 
for the translation that did this.  I couldn't find it, but the "Bcc:" header 
was definitely gone by the time the message came back to me.

My expectation was that your description is correct: the e-mail client (i.e., 
PMMail) should strip the Bcc: line out before sending it via SMTP.  That's 
the way I've always done it when I've written e-mail clients.  However, it 
appears that sendmail, at least, will take care of it for us if we forget.

--
- Tim Roberts, timr@probo.com
  Providenza & Boekelheide, Inc.


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