sender address of reject messages

Daniel Nilsson dnilsson at
Tue Aug 19 12:47:49 EDT 2003

Rob Siemborski wrote:
> On Mon, 18 Aug 2003, Daniel Nilsson wrote:
>>I played around with this for a while, and I was able to make cyrus change
>>the header of the reject message to be doublebounce at But from
>>looking at the source of cyrus, it seems like the from address in the
>>envelope of the reject message is set to <> (lmtpd.c lines 502-503 in
>>cyrus-imapd 2.0.16). I guess what happens then in my case is that the
>>reject messages have an empty envelope from: address and when the spammers
>>domain MTA doesn't want to receive the message from our mail server (since
>>the user doesn't exist for example) sendmail decides to alert the local
> From RFC 2821:
>    This notification message must be from the SMTP server at the relay
>    host or the host that first determines that delivery cannot be
>    accomplished.  Of course, SMTP servers MUST NOT send notification
>    messages about problems transporting notification messages.  One way
>    to prevent loops in error reporting is to specify a null reverse-path
>    in the MAIL command of a notification message.  When such a message
>    is transmitted the reverse-path MUST be set to null (see section
>    4.5.5 for additional discussion).  A MAIL command with a null
>    reverse-path appears as follows:


Thanks, now I understand why cyrus works the way it does. So I guess my 
problem is more of a general sendmail configuration questions them, for 
which there are more appropriate lists. But I'll ask it here anyway, in 
order to complete the thread.

When the cyrus user on our mailserver tries to send a reject message it 
sets the null reverse-path and the empty FROM address per RFC 2821. The 
problem is when delivery of this reject message fails (due to a 
non-existing user to deliver it to for example), there is no sender to 
send the failure notice to and sendmail then decides to deliver it to 
postmaster on the local machine. Is there a way I can prevent sendmail 
from doing so ? That is: when a locally generated mail with an empty 
reverse-path and FROM address fails to deliver to the recipient, how can 
I make the failure notice go into the bitbucket /dev/null ?

Daniel Nilsson
Signal Integrity Software Inc.

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