Linux off-line mailing method (offline mailaddr with 1 account)
Use your linux mailing system offline, receive mail for multiple users with only one email address, and without being 24-24 online on the net. If you are unable to pay a direct line to stay online for 24-24 and still want your users to receive mail on your linux box; as well not pay for a multi-drop box at your isp, you can use this system using only one email address to divide to your users email addresses. It is as well 24-24 reachable since the server where your account resists will receive the mail. This howto is Copyright (c)1997-98 by Gunther Voet.
- 1.1 Legal stuff
- 1.2 Copyrights
- 1.3 Feedback
- 1.4 Distribution
- 1.5 Changes
- 1.6 What am i using ?
- 1.7 Thanks go out to ...
- 2.1 Preface & Description
- 2.2 Points of interest ...
- 2.3 Things you should know
- 2.4 there are 2 different ways ...
- 3.1 A linux machine
- 3.2 A extra account at your linux machine
- 3.3 Fetchmail
- 3.4 Procmail
- 3.5 A mail account
- 4.1 Creating a .fetchmailrc file
- 4.2 Creating a .procmailrc file
- 4.3 "nosuchuserfile"
- 4.4 "crontab files".
- 4.5 "At the admins site".
- 6.1 The automation script just doesn't work:
- 6.2 What do you mean by "anonymous mailserver"?
- 6.3 My cat died
- 6.4 My dog died
- 6.5 Linux?
- 6.6 Can you help me with finding a mail account?
- 6.7 Why is the "maybe later i'll make some addition ..." removed ?
- 6.8 How do i get a "domain" ?
- 6.9 Why are you so f*cking lame using this?
- 6.10 Nosuchuserfile?
- 6.11 Can my users write/send mail too?
- 6.12 Does every user need a shell account at my server?
- 6.13 skeletion?
- 6.14 Addmail?
- 6.15 Why are you so cruel?
- 6.16 Didn't you get a complaint of excessive language ?
- 6.17 Why is this howto different than most others?
- 6.18 locally my domain works, but remote it seems not to receive
- 6.19 My dog died
In this chapter i'm just going to put myself safe for any damages and flames - since even *I* could be wrong ... If you got any questions or suggestions to add to this faq, even if you find any faults - there is a feedback section in it ...
Some "need to know" point is, all filenames & files/types are indicated with the line:
(*** < file > *** text ***) .procmailrc
This means, this is a file, called ".procmailrc" containing text. The text variable can also be code. It shows you what name of file to use. Without a path means it can be variable/choosen by you (in the most cases this files resists in the homedirectory of the mail"user" like /home/mailer).
Neither the author nor the distributors of this HOWTO are in any way responsible for physical, financial, moral damage incurred by following the suggestions and examples of this text. The information in this document contains the best of my knowledge and experience, but i could still make any mistakes as well in the information as in the examples. Any trademarks are property of their respective holders (i ain't using any commercial thingy's here - but well - IF i'm going to add some text, i don't need to change this disclaimer). If your cat dies 'coz this document was too heavy - i am not responsible as well ...
*PLEASE* *IF* you are going to make a system based on this HOWTO, then PLEASE give me the copyright :) heh ... - i am not that cruel :)). I mean by a system "a package" - NOT the mailsystem itself - altough it is some appreciative thingy i would be included :)) i can always use one email address more for more flaming :)) (just kiddin').
The latest revision of this document can been get from:
(also checkout http://tuc.ml.org)
tuc.ml.org could be down at the time of current writing!
I'm using Linux 2.0.30, Pentium-166, ATI pci-mach64 card, Accelerated-X (Metro) and a connection to my isp (currently ibmnet) via ppp using a ZyXEL 28k8 modem, and occasionally a Bausch 28k8.
Now i upgraded to Linux 2.0.33, installed a USRobotics modem, it still works as it should work :) (everybody should upgrade their linux versions as soon there comes out a patch :) believe me :) you could spare a lot of time & seeking for errors when doing this one :)
- Fred, durban.hebel.net (for allowing the pages & bot)
- Lifesaver, parkside.net (for allowing the new pages, helping with this faq for mailing, since, it is all working overthere and here ... make some visit to his cyber-cafe ... heard they got great coffee :))
- The server admins at lodus.net to continue this project.
- Now i'll need a new server since lodus.net has been sold :(
Well, how does this system works ? what can you do with it ? what is it anyway ? and ... am i used to read it ? ... to all those questions - there is an answer ...
This HOWTO is dedicated to all the off-line linux users/servers ... You got a group, or organization, and you want all your members to have a contact (email) address, without paying for the 24/24 direct line or for the email accounts ... Or you got a internal network - with a masq'd server and you want to give all the users using it a email address, you could use this way to do it. I personally am using it to give my users & members of a demogroup all a e-mail account without being 24/24 online; since it is a non-commercial demogroup - and we don't got THAT much money to pay a direct line with instant email access - and different ip's. Everybody got a email address, even when they don't got internet access. The ones with internet access can receive their mail on their personal email address - viavia the system described below. Your users can still send mail as they used to do, since - your system will hold the mail queue from the users. The only thing what should be changed for the users - is that they add their "email address" wether (described below) it is the method with the subject line, or with the header "to" ...
- A organization with members, for all a email address, so they can be contacted when neccesary.
- A anonymous mailservice - they can't read your "mail setup file" - so they don't know where the mail is forwarded/rerouted to.
- A group who doesn't got enuf money (don't laugh), or is free, and don't WANT to spend money for it (eheh) - and still wants to provide the members a email address.
- A masq'd network - with a server connected to the internet, where the users using the masq'd network need to have a email account
- You only need one account at the "main" server to fetch from, for the +200 email accounts you can create at your server ...
- I used the "B" method with +- 300 email accounts - with a public server; 80486DX4-100 - and was processed in 1 minute.
- Not every (free) mailservice is happy when you are going to distribute mail to other users, or putting up an anonymous mail server, so, please try to contact your mailserver administrator before "just doing it".
- It is slower than a direct 24/24 connection, since your server will need to get online before it will process the mail.
- It needs a administrative force to administrate the "mailrouting" and to add the user ... you will need work with it ! - it is not that automatic. (well - i made it "semi-automatic" with my server :) you could try it as well).
- Bandwidth and space is needed when you got many users - on the mailserver you are working on ... and sure - when they send files - you need to have enough space on it !.
- All mail will be transferred into "one step" - so - the last mail received on your server will be last sent to the recipient. "first in - first out".
- In the first method (to:) there is no prob with the usernames - but in the second "cheaper" method - users can't put in a subject line, since that one will be used to send the mail to the recipient. Many users forget to use the "subject" ... - or they will need to know it clearly.
- If you poll enough for your mail, (for example 4 times a day) - the mail will be sure be delivered to as from a recipient the least every 6hrs. So the processing will go a little smoother.
- you CAN use it as a "online" mail server as well :) since it will poll for it's mail for every XX minutes. but - when you are online - why using another server ? and not asking your own domain for your own server ? (dough).
- method 'A' - now called "(m(A))". The "mailsystem" will look to the header, and will see to the "to:" line. This is the best way, since it are "real email addresses". You will need another account on some server *AND* you need a DNS (MX) entry (your own domain for instance). If the system administrator wants to help you with that, then there will be no problem !. The system administrator will need to reroute ALL mail sent to your (MX) maildomain -> to your account !. This will take some time for him to do it :) so be really nice to him :)) Thanks to my system administrator (Fred) i got my maildomain and the user- services of my "free" demogroup. It can be a DNS entry costs something, what you will need to consider to take it or not.
- method 'B' - now called "(m(B))". The "mailsystem" looks to the subject line, and will forward to the user indicated into the subject line. If the user is not found, it will bounce a mail back. This will need a pop server with only one useraccount, and don't need your own DNS or you don't need to be nice to your system- administrator who arranges you the mail address :). You can use a public mailserver, as well your own mailserver or a private one. You can even sacrifice your own email address for it :). I used this approach as first what worked for me for over a year now ... I know this is sloppy, but, i ain't telling you need to use this way, so don't shoot ME - since i'm only offering you some solutions to your mail problems :) - you could use method A what isn't that sloppy !
Well, you need (of'course) a Linux machine, what can be connected to the internet - So! (i am smart - i am smart :)) - you probably got a modem, right? a phoneline - or any way to connect yourself with the server you are running. You will also need some software like Fetchmail, Procmail, an extra account, and your email account or DNS with email account.
This can be ANYthing ... even a 8086 ... - but preferable - since there will be some load on it - minimally a 80386 :). as faster the machine - as faster the software will run (rite eh)? :).
You need to create a extra account on your Linux machine. I am using as example (in this HOWTO) "mailservice". This can be as well "mailserver" or "mailtousers" - as long it is some name what can be recognized by you!.
! It doesn't need to have ANY root privileges !
This mailaccount will forward all mail to the users on your system, or to external users (not on your system :)). Just create it as an ordinary user. You will need to test things under this account, and, the mail "administrator" can use this account to administrate the mail account without being root even .. so - pretty safe !.
I am using v1.9 patch level 9 ... i found it at sunsite.unc.edu, and, i am using only this mail-fetcher in my example - if you want to use another one, you are on your own ! since i am happy with it :). For extended features you should read the man of Fetchmail :). This can be installed as root - as well for the user itself ... - best is to install it as root :) since i know it will work for sure then :)))
I am using v3.10 - found it again at sunsite.unc.edu, and - i like this as the best mda (mail delivery agent) around ... It delivers nicely - and it is better than using it by the "original" system mda - since it will deliver user-per-user ! ... The same as above - it can be installed as root, or as user - and :) best is to install it as root - since i know it will work for sure then (again!) :)... how repetetive ...
You always need to have a mail account - where you can "poll" your mail from. The server needs to be a POP server - where you can poll from when you want, and where users can send their mail 24/24 to. It can be a free-mail service, as well commercial - even your mailaccount is sufficient enough. In the "subject" method (m(B)) - you don't need something more - in method A - with the "to" fields - you NEED more - as written below !
A DNS record (MX)
Needed to run your own "domain" - email domain ... it is needed since the administrator of the server can't use it's own domain for your users - since there are users who need to be contacted on his server as well - what could interfere with your users. And your mailheader must be filtered on that domain. So - an apart domain - pointing to HIS server. This can be an additional cost - or you can ask your system administrator to add a "non- authorative address" - pointing to his server ... - however - it needs to be another domain than he is using !
A "forward" to your account-account :)
Well, the system administrator needs to forward *ALL* mail to your domain to YOUR account ... - it is easy for him when he knows how to do it :) .. else he will need to read the sendmail manual :)) (or qmail - whatever). You will poll for your mail at your account and voila ! filtering on YOUR own email domain.
Now you created the extra account, you got the mail address - and/or the DNS entry & forwarding to your account ... As well installed Procmail & Fetchmail so we can rock the place ! :) .. here we go !
- You need to create a .procmailrc file, what will contain the "delivery" info to your users.
- You need to create a "nosuchuserfile" - so the writer knows his mail isn't delivered well.
- For best work :) you could use crontab to check for mail. This is a easy way to check your mail every XX minutes when on the internet.
You will need to create a .fetchmailrc file, what will contain the information (username & password, as well the Mail Delivery Agent (mda) to proces the mail to). Here is some example file ...
(*** < file > *** text ***) .fetchmailrc
server my.mail.server.com proto pop3 user myaccountthere pass deepestsecrets flush mda /usr/bin/procmail
This file will be used to fetch your mail. Please test it by using the fetchmail program "fetchmail -vv" - and see your mail is being transferred right ... There will be some errors - since the procmail control file hasn't been created yet. You can wait by testing AFTER making the procmailrc file, but - i'll warn ya - IF there is something fault :) it CAN be this file :) It needs to be owned by the user account itself - in my case "mailservice" and needs to be "user readable" but NOT group/world readable - since it contains the "main password" :)). (chmod 600 .fetchmailrc will do).
This control file will forward all mail to the users in it. There are 2 ways as described before - the "to:" (header) way - and the "subject" (sloppy) way. The file will contain the usernames to transport to. All the "#" are comments and are absolutely not needed when not wanted - it's only so you know what i am doing ... - you can as well best chmod it 600 - so the rest of the world or group doesn't need those private addresses eh :) ... It needs also to be owned by the user (like "mailservice") :)). The "nosuchuserfile" is a "bounce" to the writer - if the user isn't found (so mail not delivered) in the procmailrc file ... - so the writer knows the mail isn't delivered well.
For "header (to:)" transportation
(*** < file > *** text ***) .procmailrc
For "subject: touser" transportation
(*** < file > *** text ***) .procmailrc
(*** < file > *** text ***) nosuchuser
The user you wanted to contact is not present at this system. Please use the subject line as recipient - example "subject: freaker" would send mail to freaker on this system.
If you don't know how crontab works :) better read the manual :) ... You need to create a "checkmail" file - what will see if the link is up, as well the cronfile itself ... - i am using a ppp link :) so - this is an example how to look when the ppp link is up - and to poll every 10 minutes using cron. Looks sloppy - but isn't !.
the .checkformail file will be called (needs to be executable as well) - and will look if the ppp link is up. If it is up - then it will fetch for mail. Crontab will use this file when you are using the below cronentry ...
(*** < file > *** code ***) .checkformail
#!/bin/sh # cd /home/mailservice if [ -f /var/run/ppp0.pid ]; then /usr/local/bin/fetchmail -s > /dev/null 2>&1 fi
This cronentry file needs to been loaded into crontab, and will call the .checkformail - every 10 minutes. It won't write any mail or give any info to the console - since i'm redirecting everything to null.
(*** < file > *** text ***) cronentry
0,10,20,30,40,50 * * * * /home/mailservice/.checkformail 1> /dev/null 2> /dev/null
Well, this should be done when using the "A method" ... at the admin's site, so the email goes all from a complete domain, to one username. It is pretty simple, and once you've done it - it works like hell. this is NOT neccesary if your system administrator (the uplink) got another method, and is NOT neccesary at YOUR side !!!!
When using a newer version of sendmail, the "old sendmail" trick probably won't work, so please refer to the "new sendmail" topics to let your mailrouting work.
(old sendmail) add some lines to sendmail.cf
add the following lines to your /etc/sendmail.cf file, so the domains file will be read. please be noted that the "ruleset 98" is added as underhere, since - once you got errors :) it's a hell to find 'm out ! (and i can know it :) DuH).
(*** < file > *** add ***) /etc/sendmail.cf
# Database of handled domains Kmaildomains btree /etc/maildomains.db # Add these lines *IN* Ruleset 98 ! (under Ruleset 98). R$+ < @ $+ . > $: $1 < @ $2 > . R$+ < @ $+ > $* $: $(maildomains $1@$2 $: $1 < @ $2 > $3 $) R$+ < @ $+ > $* $: $(maildomains $2 $: $1 < # $2 > $3 $) R$+ < @ $* > . $: $1 < @ $2 . >
(new sendmail) Adding some lines to sendmail.cf
With the newer sendmail releases (tested with sendmail v8.8.7, 8.8.8). Ignore method A, and add the next lines ...
(*** < file > *** add ***) /etc/sendmail.cf
# Database of handled domains Fw/etc/sendmail.cw Kvirtuser btree /etc/maildomains.db *OR* Fw/yourhomedir/sendmail.cw Kvirtuser btree /yourhomedir/maildomains.db
(new sendmail)editing the /etc/sendmail.cw (or /yourdir/sendmail.cw) file
If you are using another "location" for the sendmail.cw file, then please replace the "/etc/sendmail.cw" to "/yourhomedirectory/sendmail.cw". The pro points of putting this sendmail.cw file into your homedirectory is that you don't need root to change the domains to receive on. tough - this can give security risks if not used properly !
This file can already exist, or needs to be created, if it already exists be sure you don't overwrite the older data - or i need to refer you to my fine disclaimer :)
First create a /etc/sendmail.cw file, what will be used to "send" a domain to a specific user ... here is an example ... (as you already knew, the name "mailservice" can be anything you want - it can even be your loginname (like mine is freaker).
(*** < file > *** text ***) /etc/sendmail.cw
creating a /etc/maildomains file
First create a /etc/maildomains file, what will be used to "send" a domain to a specific user ... here is an example ... (as you already knew, the name "mailservice" can be anything you want - it can even be your loginname (like mine is freaker). (you could have this /etc/maildomains in /yourhomedir/maildomains as mentioned before, just change the paths :)
With the OLDER sendmail versions:
(*** < file > *** text ***) /etc/maildomains
With the NEWER sendmail versions:
(*** < file > *** text ***) /etc/maildomains
let it work !
With the old & new sendmail versionsyou need to generate the btree (database) files, you'll need to do the following:
cd /etc (or /yourhomedir) makemap btree maildomains < maildomains
after that, kill the sendmail daemon, and restart it. it should now WORK! good luck :)
Well, now, everything above works ... (if it doesn't work - don't even think about automation before it WILL work ... - now - we need some script so it isn't a pain in the ass for the "mailadministrator" or the root user to add users to the procmailrc file ... The below example will be for "more experienced users" - since some things NEED to be changed as well ... - it is an example with the "B method - Subject lines". It can be easily adapted to the "A method". Since the "B method" will be more used (cheaper) than the "A" method - i decided to use the "B method" ... Am i sounding repetitive or not ? .. well - i meant to write it in this way :)) to bug you :)))..
Since the footer needs to be as footer (everything below won't be processed since we are bouncing there); there needs to be a header and a footer file.
the ".procmailrc-header" file
This file will now be the "header & user" file .. since here will users been added and removed - it will be a important file ... - best take a backup from it each time you add a user ... - there COULD be something wrong sometime .. A system can fail ...
(*** < file > *** text ***) .procmailrc-header
the .procmailrc-footer file ..
As mentioned above, this file needs to be as footer - since all data BELOW it won't be used to deliver - this footer contains the "bounce" code to bounce the users not found *ABOVE* this footer !. it is the ABSOLUTE end of the file !
(*** < file > *** text ***) .procmailrc-footer
This script will add a user to the header file, attach the header & footer to eachother - so it will be a complete .procmailrc file. the "#" (comments) are not really needed - and are for your info :).
(*** < file > *** code ***) addmail (* chmod 500 *)
Now, this script will append the information of the user, as well the email address to the header file, it will copy it to the .procmailrc file, and will add the footer to it, so you got a complete .procmailrc to process the mail. If you want to delete a user- just edit the .procmailrc-header file, and at the next user added it will be deleted at the .procmailrc. To do a instant delete, just delete the user from both the files .procmailrc & .procmailrc- header.
I guess you are smart enough to write a script that'll automatically add your users when using both methods - when doing a "adduser" at your box.
Well, you need help - isn't :) ... hmm .. i could be sarcastic and just say "you could better do it again, 'coz it looks a messy enuf" - or .. i could help ... - I wrote down some common problems - IF you got any problem NOT listed in this HOWTO (section) - then mail me - and i'll put it in this howto even with your name/email addr in it :). **BEFORE** mailing to me - please look if you didn't forgot anything - and IF you want some help from me - send me the MOST DETAILED information - included the scripts & things you needed. i DON'T need any binaries - since i won't run them.
- is it executable ?
- is your (default shell) located at /bin/sh ?
- Well, next time don't print this HOWTO out on 200 gram papers, since it are 10 pages it would be 2KG for the cat - it is JUST TOO HEAVY !
- hmm - can't do anything about that one - why askin' me ? ... Just bury it ....
- A free-unix - posix compatible - made by Linus Torvalds ... Why are you reading this if you even don't know what Linux is ?
- No! - this is a howto for YOUR side, i don't care about the side of your isp, nor how to get your email address.
- Read point 5.5 very carefully :) and you'll see why .. it's 'coz i needed to add it on general request :)
- Ask your local ISP/provider - he will help you with it. It could take days/ even weeks when asking to the Internic - your provider can help.
- coz i don't want to spend money - and - 'coz i feel like being f*cking lame USING it - i *AM* using it - so why bother?
- You can put in it what you want - as long you put some "needed" info so the original writer knows what happened with his "never delivered" mail.
- This has nothing to do with the system i explained to you, read the sendmail manual ... - this is to RECEIVE mail - to be "always available at an email address".
- Nope .. - but - it will be really hard for users not having internet access :) ... You could have a masq'd network - and use a computer connected to it - so the users can get their mail that way, or you can generate a link between a bulletin board and his mail, you could even forward it to a fidonet gate :) ... reasons enough not to give a shell!.
- i know it is a typo - but - i like this word better.
- No questions - for automation - you better be sure about what you are going to do ... since - it COULD be a trojan ya know :))) (it isn't but what means you need to know what scripting is before asking questions) It IS easy enough to interprete - that's even why i put the comments with it. *IF* you are going to distribute this script - leave my Copyright in it please ! thanks :).
- I am not cruel :) i am nice :) i am the nicest guy of the world, of the universe ! NOW SCRAM! (i just want to be complete in my HOWTO, and not TOO much "drifting away" from my original point in the doc - so :) that's all).
- Not yet, but, could be i'm filtering everything containing 'excessive' and language :) i don't know :))
- coz sometimes reading plain howto's CAN be boring ... i wanted to add something next to it ...
- Check out your "sendmail.cw" file, since the domains NEED to be added in it !
- the rulesets don't work, i can't receive any mail, or sendmail dies Refer to the new section "new sendmail" - and disregard the old sendmail tricks. The newer sendmail should be easier to use with virtual domains.
This sounds like the end ... If you find any unwanted bugs (or features :)), then leave some feedback ... any comments & suggestions -> mail them :). if you are still bored after reading this, please go to: http://tuc.ml.org/ hehehe.
My thanks go out to:
Hannes van de Vel: for supporting me (hum) Tetsu Isaji: the japanese offline-mailing & notifying me about errors :) Greg Hankins: for notifying me about some errors in the sgml version. Linus torvalds: of'course ... without his help this howto wouldn't be here!