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ISP-relay SMTP question
by ted.harding＠nessie.mcc.ac.uk 15 Nov '07

15 Nov '07

Hi Folks, I'm hoping someone with the expertise can help me! In connection with trying to diagnose email delivery problems to a particular domain, I'd like to know the answer to the following. My email procedure is: 1. Compose the email "off-line" in my MUA (XFMail) 2. "Send" it -- so it goes in the outbox 3. Really send it (batch send) -- XFMail hands the outbox over to sendmail which then does SMTP with the mail server of my ISP (Zen). Up to this point, there is no problem; and receipt of a "check" Bcc: sent to me on an external email account via the ISP verifies that the ISP accepted the mail for delivery. And of course I usually have no problems with delivery of emails to their destinations by the ISP. Except for this one domain. Now the question. When my sendamil is doing its SMTP with Zen's mail server, the first substantive request it will make is mail from: <whatever.my.sendmail.uses> After the mail has been received by the ISP, the ISP's mail servers will try to initiate connections with the destination domain's mail server. Again, once a connnection is established, the first substantive request it will make will be of the form: mail from: <whatever.my.ISP.uses> My question is: What (if any) is the relationship between <whatever.my.sendmail.uses> and <whatever.my.ISP.uses> ?? Does <whatever.my.ISP.uses> take the email address from the "From:" header in the email? From the "envelope-from"? Or does it uses its own version, as in (e.g.): mailer-daemon(a)zen.co.uk Or what? One aspect of the background to this question is that, when I try myself to do a (test) manual SMTP dialogue with one of the remote domains mail servers, while I may well get through and successfully send the mail, on many other occasions I will get a response to "mail from:" on the lines of mail from: Ted.Harding(a)manchester.ac.uk 451 4.3.2 Please try again later which will be repeated indefinitely if I keep trying. So I'm wondering if it may be a negative response to the email address used in the "mail from:" request, or has some other reason. Since I don't know whether Zen's mail server would use the same (or similar) email address in its own "mail from:" request, I can't (as yet) link the delivery failures I get with my own SMTP dialogue with the delivery failures when Zen tries to forward my emails to the destination domain. [And, by the way, how should I interpret the error message 451 4.3.2 Please try again later ??] With thanks, Ted. -------------------------------------------------------------------- E-Mail: (Ted Harding) <ted.harding(a)nessie.mcc.ac.uk> Fax-to-email: +44 (0)870 094 0861 Date: 15-Nov-07 Time: 11:36:23 ------------------------------ XFMail ------------------------------

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Motherboard memory problem
by Chris G 15 Nov '07

15 Nov '07

I have just bought an extra 4Gb memory for my Abit AB9 Pro motherboard, I have plugged it in and it works fine (so I now have 6Gb) but I'm not convinced I understand the optimum way to install the memory. There are four memory slots numbered 1, 2, 3 and 4, they are laid out as two pairs, 1 and 2 close together and 3 and 4 close together. The manual is very ambiguous/confusing, it says:- To reach the optimum performance in dual-channel configurations, install identical DDR2 DIMM pairs for each channel. So does that mean a matched pair in both slots of channel A and a matched pair in both slots of channel B? That's not how the dealer had installed the existing memory and it isn't how their examples are either (see below). It's pretty definite that Channel A is slot 1 and slot 2, Channel B is slot 3 and slot 4, that at least is clear enough. However this is where it gets confusing, the sample layouts are for "Dual Channel Asymmetric" and "Dual Channel Symmetric", it doesn't say which is the best and they don't make a lot of sense. For example some "Dual Channel Asymmetric" layouts are:- Slot1 256Mb, Slot2 256Mb, Slot3 512Mb, Slot4 512Mb Slot1 256Mb, Slot2 256Mb, Slot3 256Mb, Slot4 512Mb Whereas a "Dual Channel Symmetric" examples are:- Slot1 512Mb, Slot2 empty, Slot3 512Mb, Slot4 empty Slot1 256Mb, Slot2 256Mb, Slot3 empty, Slot4 512Mb Slot1 256Mb, Slot2 512Mb, Slot3 256Mb, Slot4 512Mb Slots 1 and 3 are pink, slots 2 and 4 are red. I *suspect* that I have it right, as follows:- Slot1 1Gb, Slot2 2Gb, Slot3 1Gb, Slot4 2Gb (the dealer installed 1Gb were already in slots 1 and 3) but I'd really like to *know* that I have it right! -- Chris Green

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Re: [ALUG] more about sendmail
by mbm 13 Nov '07

13 Nov '07

>> You shouldn't use a CNAME for a host that you want to receive mail. I >> suggest you try changing it to an A record instead. > > To quote RFC1123 section 5.2.2: > > The domain names that a Sender-SMTP sends in MAIL and RCPT commands MUST > have been "canonicalized," i.e., they must be fully-qualified principal > names or domain literals, not nicknames or domain abbreviations. A > canonicalized name either identifies a host directly or is an MX name; it > cannot be a CNAME. > > Can someone explain why this restriction exists (or point to a good resource)? One obvious point is DNS inefficiency. If the sending MTA gets back an answer to an MX query pointing to a CNAME it then has to query again to get the A record. If there is a CNAME chain (and there may well be) then there have to be multiple queries until the A record is reached. Check out the Bat book. Mick

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More about sendmail sending to local machine
by Chris G 13 Nov '07

13 Nov '07

I'm beginning to think this is impossible! :-) I've been doing some Google searching about the file local-host-names, one hit suggested trying the following to see what sendmail views as local domains:- echo '$=w' | sendmail -bt ... and what does it return .... ADDRESS TEST MODE (ruleset 3 NOT automatically invoked) Enter <ruleset> <address> > home home.isbd.net localhost [192.168.1.1] isbd.net Which certainly looks as if sendmail thinks that home.isbd.net is the local machine. However when I tried using 'mail' to send a message from root to chris(a)home.isbd.net (I used 'mail' to ensure little else was involved) it *still* tries to send it out to the outside world. The entries in maillog are:- Nov 11 11:38:20 home sendmail[7883]: lABBcJ9h007883: from=root, size=64, class=0, nrcpts=1, msgid=<200711111138.lABBcJ9h007883(a)home.isbd.net>, relay=root@localhost Nov 11 11:38:20 home sendmail[7884]: lABBcKac007884: from=<root(a)home.isbd.net>, size=354, class=0, nrcpts=1, msgid=<200711111138.lABBcJ9h007883(a)home.isbd.net>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1] Nov 11 11:38:20 home sendmail[7883]: lABBcJ9h007883: to=chris(a)home.isbd.net, ctladdr=root (0/0), delay=00:00:01, xdelay=00:00:00, mailer=relay, pri=30064, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (lABBcKac007884 Message accepted for delivery) Nov 11 11:40:20 home sendmail[7886]: lABBcKac007884: to=<chris(a)84-45-228-40.no-dns-yet.enta.net>, delay=00:02:00, xdelay=00:02:00, mailer=esmtp, pri=120354, relay=84-45-228-40.no-dns-yet.enta.net. [84.45.228.40], dsn=4.0.0, stat=Deferred: Connection timed out with 84-45-228-40.no-dns-yet.enta.net. -- Chris Green

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How to send mail locally, solved but I don't really understand why
by Chris G 11 Nov '07

11 Nov '07

Well I finally found a way to send mail to local recipients, quite by chance really. I have a POP3 mailbox set up at Gradwell.net to allow me to send mail to 'myself' on my home machine (I read just about all of my mail on a remote machine at Gradwell) which comes in useful occasionally when I want to send a file to my home Linux box. This is set up in my isbd.net on Gradwell so it's home(a)isbd.net. I just occasionally run mutt locally on my desktop machine and collect mail from this POP3 mailbox. So, I realised that one way around my problem of sending mail to myself on the desktop machine would be to put home(a)isbd.net as the alias for root mail in /etc/aliases. Before doing this I tried sending mail to home(a)isbd.net from my desktop machine, it failed with "Error sending message, child exited 67 (User unknown.).", huh? I then realised that this meant that sendmail was trying to send this *locally* and there's no user called 'home' on this machine. Euraka!!! If I send mail to chris(a)isbd.net on my desktop machine it gets sent to the local user chris and *not* to the place where it would get sent if it was sent from anywhere else on the internet (chris(a)isbd.net is one of my 'real' E-Mail addresses). So, problem solved, I can put:- root: chris(a)isbd.net at the end of /etc/aliases and all the root mail will get to me locally. Quite *why* it's like this is anybody's guess! :-) -- Chris Green

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How to get mail to local destinations delivered?
by Chris G 11 Nov '07

11 Nov '07

I have a fairly default Fedora 7 installation, certainly the sendmail is just as it was installed. How do I get sendmail to deliver mail to local destinations? The system's hostname is home.isbd.net and it's connected to the Internet via a router. I have a CNAME set up at the hosting provider that hosts isbd.net to point at the static address of my ADSL connection. When I send mail from my system to a local address it gets the hostname added, thus mail gets sent to root(a)home.isbd.net, postmaster(a)home.isbd.net, chris(a)home.isbd.net, etc. All of this fails because sendmail attempts to connect to the SMTP port of home.isbd.net, which isn't possible because my router's firewall doesn't accept connections on port 25. I don't want to open up port 25 and it seems a bit silly anyway to send mail on such a long round trip. Is there any way I can tell sendmail that home.isbd.net is localhost (or 192.168.1.1)? I have an entry for home.isbd.net in my /etc/hosts file which is:- 192.168.1.1 home home.isbd.net but obviously sendmail is doing a DNS lookup for home.isbd.net which returns the 'external' IP address. -- Chris Green

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Regex
by Ruth Bygrave 11 Nov '07

11 Nov '07

In a more-stupid-than-normal moment I ended up with a Text Edit document on my Mac with lots of capital I's in the middle of words. I tried 'check spelling' to see if it did an entire run of spell- checking through the document, but there was no dialog box. Tried to go through it in NeoOffice, which I'm not that familiar with, but NeoOffice bombed. Can somebody less brain-dead than I appear to be today come up with a bash script to pour the text into that does 'replace I not on word boundary with i'? (The infuriating thing is, I used to *know* this stuff, or at least where to look it up, but because I've been Abjuring Hackish Unixy Things since I was in mental hospital this summer, I don't even know where to start...) Also 'replace 'fI ind' with 'I find', because the reason I was messing about with I's in the first place was there's a timing error with my Alphasmart Neo keyboard and it has a tendency to transpose letters. Kthxbai, Ruth

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Samba question/problem
by Chris G 07 Nov '07

07 Nov '07

I have Samba installed and working on my Fedora system, it mostly does what I expect but one entry doesn't. My smb.conf file has:- # global section default service = default encrypt passwords = yes null passwords = yes workgroup = IBMPEERS nt acl support = no [snip] # # # ISBD, user is set to isbd to allow read/write # [isbd] comment = ISBD force user = isbd path = /home/isbd guest ok = yes writable = yes By my reading of the smb.conf manual page that should allow anyone in to access /home/isbd, it should make them act as the user 'isbd' and it should give write access. (Remember this is a home intranet, two users, who both want access to the ISBD files) In practice when connecting from XP I always seem to have to enter a valid password to get access. In general what's the easiest way to make Samba shares appear in XP 'automagically' without having to enter passwords etc.? -- Chris Green

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Python question about reading files
by Chris G 06 Nov '07

06 Nov '07

Are there any Python people here? How do I do the equivalent of the C below in Python :- while ( (str = read(file)) != NULL) { do something; } I can read the data OK, i.e. I have opened the file and I can successfully read from the file with the line:- tagNum = tlvFile.read(3) but I don't see how to make that part of a for/while loop that exits at the end of the file. I can't use an iterator because the file is read in variable length chunks whose length depends on context. -- Chris Green

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BBC on amarok or whatever, how to?
by Peter Alcibiades 06 Nov '07

06 Nov '07

I'm seeking (for someone else) to get streaming BBC to play over some Linux player, don't really care what, on 64bit Debian. Once more cursing the day I ever installed 64 rather than 32bit, and on more than one machine, but that's another story. Amarok, attempting to tune into (for example) mms://wmlive-acl.bbc.co.uk/wms/radio1/radio1_nb_e1s1 gives the response Error loading media, there is no available decoder. I set up amarok in accordance with these instructions: http://www.linuxforums.org/forum/gaming-games-multimedia-entertainment/7934… and presumably having got to the point of trying to play, probably did it right. Assuming this is because there is no win codecs, I went to medubuntu and got the 32 bit ones. This was a large weighty package. They will not install being 32bit. OK, went back and got the 64 bit amd64 ones. This was a suspiciously small file, and one's fears were realized when the package installed and the message was unchanged. I have also downloaded Real Player, and made it executable, but now what to do with it? It too of course is 32bit and presumably that is why it will do zip when you try to start it. There is no problem downloading the mp3 files for previously broadcast programmes, and they play just fine (rhythmbox seems to be an acceptable interface for this). But what I'm really being asked to provide is streaming BBC internet radio. Anyone done it? Peter

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