[fetchmail-devel] Fetchmail bounce message

[Nico G. <ni...@ng...>]

Hi,
this is the newest bug in the debian bts:
When the local SMTP daemon rejects a message, Fetchmail generates a 
bounce messages with a non-null reverse-path, in violation of RFCs. In 
addition, the username it uses (FETCHMAIL-DAEMON) does not exist, so any 
responses will themselves bounce. This is likely to generate mail loops.

Also the message it sends has no subject, which is very unhelpful.

fetchmailrc:

set daemon 60
set postmaster "postmaster"
poll pop3.demon.co.uk aka mailstore protocol SDPS interface eth0/192.168.0.1
    options localdomains rilynn.demon.co.uk no dns no envelope
    user rilynn password foo to *
        options fetchall no rewrite warnings 86400

The relevant part from fetchmail -v -v is below:

reading message ri...@po...:1 of 1 (1683 octets)
fetchmail: passed through gf...@ri... matching rilynn.demon.co.uk
fetchmail: SMTP< 220 rilynn.demon.co.uk ESMTP Exim 4.50 Thu, 30 Jun 2005 23:36:27 +0100
fetchmail: SMTP> EHLO localhost
fetchmail: SMTP< 250-rilynn.demon.co.uk Hello localhost [127.0.0.1]
fetchmail: SMTP< 250-SIZE 52428800
fetchmail: SMTP< 250-PIPELINING
fetchmail: SMTP< 250 HELP
fetchmail: forwarding to localhost
fetchmail: SMTP> MAIL FROM:<ro...@co...> SIZE=1683
fetchmail: SMTP< 250 OK
fetchmail: SMTP> RCPT TO:<gf...@ri...>
fetchmail: SMTP< 550 unknown user
fetchmail: SMTP error: 550 unknown user
fetchmail: SMTP listener doesn't like recipient address `gf...@ri...'
fetchmail: SMTP< 220 rilynn.demon.co.uk ESMTP Exim 4.50 Thu, 30 Jun 2005 23:36:27 +0100
fetchmail: SMTP> HELO localhost
fetchmail: SMTP< 250 rilynn.demon.co.uk Hello localhost [127.0.0.1]
fetchmail: SMTP> MAIL FROM:<FET...@ri...>

***         Should be empty^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^  ***

fetchmail: SMTP< 250 OK
fetchmail: SMTP> RCPT TO:<ro...@co...>
fetchmail: SMTP< 250 Accepted
fetchmail: SMTP> DATA
fetchmail: SMTP< 354 Enter message, ending with "." on a line by itself
fetchmail: SMTP: (bounce-message body)
fetchmail: SMTP>. (EOM)
fetchmail: SMTP< 250 OK id=1Do7dz-0000eX-Cu
fetchmail: SMTP> QUIT
fetchmail: SMTP< 221 rilynn.demon.co.uk closing connection
fetchmail: SMTP> RCPT TO:<postmaster@localhost>
fetchmail: SMTP< 250 Accepted
fetchmail: no address matches; forwarding to postmaster.

In addition to generating a bounce, the original mail is forwarded to 
postmaster, as can be seen on the last couple of lines above. My 
understanding of the man page is that either a bounce should be 
generated *or* it should be forwarded to the postmaster address, but not 
both.

Regards Nico

-- 
Nico Golde - JAB: ni...@ja... | GPG: 0x73647CFF
http://www.ngolde.de | http://www.muttng.org | http://grml.org 
VIM has two modes - the one in which it beeps 
and the one in which it doesn't -- encrypted mail preferred