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<td width="30%" align=right>$Date: 2001/07/06 01:18:42 $
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<H1 ALIGN=CENTER>Fetchmail Bugs and To-Do Items</H1>
I try to respond to urgent bug reports in a timely way. But fetchmail
is now pretty mature and I have many other projects, so I don't
personally chase obscure or marginal problems. Help with any of these
will be cheerfully accepted.<p>
Errors in RCPT TO responses aren't handled gracefully. This shows up
if you enable FEATURE(delay_checks, friend) in sendmail, so that you
can accept mail to postmaster from sites otherwise blocked by my
access database. The effect of this feature is that the MAIL FROM:
address is always accepted OK, and any rejection of the sender is
delayed until the RCPT TO: part of the SMTP transaction. This includes
rejects such as 553 for invalid sender address. In this configuration
fetchmail cannot deliver mail with invalid sender addresses, so you'll
get lots of bounce messages when some spammers hit your mailbox (a
pair of bounces every time fetchmail runs; one to FETCHMAIL-DAEMON
generated by sendmail when fetchmail's bounce to the spammer is
rejected, and one postmaster notify for that bounce). The problem is
that fetchmail only recognises the 553 response in reply to MAIL FROM:
and not RCPT TO:, see the unused code near sink.c:690. A really
correct fix would callling a modified version of handle_smtp_error
that doesn't RSET the connection.
Using LMTP alias with a local name that is not a full name fails horribly
(the LMTP port never gets stripped off the name).
The UIDL code seems rather broken. It's a nasty swamp. Somebody who
actually uses it should fix it -- every time I try I seem to make
things worse....<p>
POP3 can't presently distinguish a wedged or down server from an
authentication failure. Possible fix: after issuing a PASS
command. wait 300 (xx) seconds for a "-ERR" or a "+OK" . If nothing
comes back, retry at the next poll event and generate no errors. If we
get an -ERR then log an authentication failure.<p>
SMTP authentication a la RFC 2554 ought to be supported. The Exim
reference has a
<a href="http://www.exim.org/exim-html-3.10/doc/html/spec_33.html#SEC705">
whole chapter on this topic</a>.<p>
It has been reported that multidrop name matching fails when the name
to be matched contains a Latin-1 umlaut. Dollars to doughnuts this is
some kind of character sign-extension problem. Trouble is, it's very
likely in the BIND libraries. Someone should go in with a debugger
and check this.<p>
In the SSL support, add authentication of Certifying Authority (Is this
a Certifying Authority we recognize?).<p>
Laszlo Vecsey writes: "I believe qmail uses a technique of writing
temporary files to nfs, and then moving them into place to ensure that
they're written. Actually a hardlink is made to the temporary file and
the destination name in a new directory, then the first one is
unlinked.. maybe a combination of this will help with the fetchmail
lock file."<p>
Move everything to using service strings rather that port numbers, so we
can get rid of ENABLE_INET6 everywhere but in SockOpen (this will get
rid of the kluge in rcfile_y.y).<p>
The <a
href="http://bugs.debian.org/cgi-bin/pkgreport.cgi?pkg=fetchmail&archive=no">Debian
bug-tracking page for fetchmail</a> lists other bug reports.<p>
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<P><ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@thyrsus.com></A></ADDRESS>
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