Re. Mail-dir hanging & needed telnet to delete bad entry.
am 14.02.2007 04:50:03 von news> > I've got an original name and an alias for my ISP's pop server.
> > Ie. 2 different email addresses at the same domain.
> >
> > I normally use an uncommon download/reader: ETH-Oberon...
> > First I download the directory,
> > Then I select entries from the directory to download.
> > I can delete individual or 'from here to the last' entries.
> >
> > Recently my ISP was hanging during directory-fetch of one
> > of my 'names'; which I could see from watching [on repeated
> > attempts] the modem leds.
> >
> > Because my ISP requires Tx-authenticate recently, I've
> > investigated using telnet to manipulate the mailserver.
> > And it also hangs for telnet, so the problem doesn't seem
> > to be on my side ?
> >
> > I've left about 40 mails on the problem directory; and
> > using telnet's "stat, top
> > I was able to determine that approx. the 75'th mail,
> > was the problem. I started by reading the headers and
> > first few lines via telneting "top"; and then deleting from
> > the highest-numbered mails.
> >
> > It's a bit tricky since the higher number mails 'fall down'
> > to fill the hole, but only AFTER log-off.
> > Apparently 'top
> > But a mail, which I think was adjacent to the culprit,
> > was seen by 'top
> > full of non-ascii chars.
> >
> > Q- is this a common fault ?
Randolf Richardson wrote:
> If the server software isn't handling this properly, then it needs
> to be fixed,
>
That's obvious, but I think it was just a freak corruption: a long
string of non-ascii-chars got into the server
>
> but it's more likely your eMail client software that
> has the problem.
No !! That's why I explained that I got the same problem with
a plain telnet access from linux, using 'TOP
> Although messages with header lines that exceed 998 characters
> (not including the CRLF line-termination characters), software
> still needs to be designed to handle such corruption in
> some way that doesn't leave the user with an unresponsive system
> (e.g., the best option is to download the message anyway, and
> then place it in a special folder for corrupt messages so the
> user can decide how to handle it later).
?! Isn't it clear from my text that I *couldn't* download "it" ?!
Because it DID make my system unresponsive.
And then using a different box with linux-telnet and doing 'top',
from the last mail, working backwards, again the system [of server
& client] became unresponsive eg. after downloading from 81
down to number 75. Which idicated the problem was mail 76,
or 75. Only after deleting mails 75 & 76 was the system free.
From this, the indications are that the SERVER was not able to
handle it.
> > Q - How would M$-outsp00k users handle it ?
> I have no idea how the users of a particular application would
> handle any given scenario.
I'm guessing that the user would phone the ISP, who whould
have to investigate, and then delete or edit the offending mail.
> > Q - can M$-outsp00k fetch just the directory first,
> > and next time online, select just particular mails,
> > and selectively delete others ?
>
> I assume you're using POP3 to download the messages, in which
> case selective mail downloads are possible with some eMail
> client software (such as Pegasus Mail by David Harris).
> I have no idea if Microsoft's OutLook even has this feature.
That sounds absurd [but believable].
If you've got a lot of BIG spams, you'll effectively have a DOS
effect, by not being able to just D/L the 'directory' and delete
the mails which are seen to be spam.
> As far as "fetching a directory," POP3 doesn't work in these
> terms. It can obtain a list of messages available during the
> current session, and then download at that time.
Wrong, here's the algorithm:
send: "STAT", which receives:
FOR mail := 1 TO noOfMails DO
send ("TOP" mail ) //which will return the header
parse the header & show eg. the date, sender, subject
END-FOR;
Hence the displayed rows of mail entries constitutes a
"directory", from where you can eg.
1. fetch selectively, 2. delete selectively or 3. delete 'all
from here to end'.
> > I think that my ISP required me to have Tx-authenticate only
> > because I wasn't using a familiar reader, because when I look
> > at mail-headers, none of them are Tx-authenticated except
> > ones which I've sent. People tell me that Tx-authenticate
> > is a common requirement.
> >
> > Q - why don't I see the Tx-authentication field filled in
> > on mails which I receive from other posters ?
> Are you referring to "SMTP Authentication?" If so, then
> people are right in that SMTP Authentication is a common
> requirement because it is often used to stop spammers from
> committing "relay rape" which means they use
> the server to send their spam to countless victims.
Yes I know the 'text book answer', but have you SEEN how
many mails which YOU receive have this field filled in ?
> > Thanks for any input,
> >
> > == Chris Glur.