[Mailman-Users] Mailman and Courier
gward at mems-exchange.org
Fri Oct 26 00:02:54 CEST 2001
On 25 October 2001, Billy Harvey said:
> The syslog shows:
> Oct 24 21:57:15 maestro courieresmtpd:
> error,relay=::ffff:127.0.0.1,ident="list",msg="554 Syntax error - your
> mail software violates RFC 821.",cmd: RCPT TO:
> The Courier FAQ says this error is usually due to the sending software
> not wrapping the RCPT TO address in <> 's.
Wow, so much for "Be liberal in what you accept, conservative in what
you emit." ;-)
> Is that the case in Mailman? Is that an easy fix on my end and if so
> any pointer to what I should change? Is it something else?
The best way to find out is to use packet-tracing software like
Ethereal. Ethereal is amazingly cool; just run it for a few seconds
while Mailman is passing a message to your MTA, find a packet from that
connection, and you can reconstruct the whole SMTP session. Question
The second-best way is: Use the Source, Luke. A quick look at
Mailman/Handlers/SMTPDirect.py reveals that Mailman uses Python's
smtplib module. Specifically, it creates an SMTP object and calls
sendmail() on it.
No wait, it uses Mailman's "custom" version of smtplib. So let's take a
look in Mailman/pythonlib/smtplib.py for the answer. Here's a snippet
from the SMTP.sendmail() method:
for each in to_addrs:
if (code <> 250) and (code <> 251):
So what we're really interested in is the SMTP.rcpt() method; here's the
relevant line from that:
self.putcmd("rcpt","TO:%s%s" % (quoteaddr(recip),optionlist))
OK, now we need to look at quoteaddr(). This function calls
rfc822.parseaddr() to extracts the bare address from a possibly-hairy
RFC-822 mailbox, eg.
"John Doe <john (not jane) @ example . net>" -> "john at example.net"
and then wraps the bare address in "<..>". (Yes, that is a legal
mailbox according to RFC 822.)
The only time quoteaddr() doesn't do that is if it can't parse the
address, *or* if the address is an empty string.
So the answer is: yes, Mailman does emit correct RCPT TO commands, but
it might screw up in pathological cases. Use Ethereal (or a similar
tool) to see what's going wrong between Mailman and Courier.
Greg Ward - software developer gward at mems-exchange.org
MEMS Exchange http://www.mems-exchange.org
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