Sven Guckes 1995-2003

Latest change: Fri Nov 28 21:42:00 CET 2003

A Guide to Life on Mailing Lists (FAQ)

What's in this FAQ?

FAQ Summary

FAQ Overview

Mutt and Mailing Lists

the command "list-reply"

Mutt features the command "list-reply" which will reply to the first address it knows as the address of a mailing list.

So you will have to tell mutt which addresses are mailing lists. You can configure this with the config command "lists":

        subscribe linux-l
Now mutt knows that all addresses which start with "linux-l" are addresses of a mailing list.

For more info see mutt's doc/manual.txt on "Mailing lists".

the mailing list "linux-l"

The mailing list "linux-l" lives in Berlin, Germany (aka Krautland). People there believe that an "open mailing list" (read: no subscription required) is a good thing. This seems "nice" - but it isn't. But let's not get into that..

The problem discussed here is "addressing". There are two addresses to that mailing list, and one of them is deprecated.

Of course, there is still the address on host "calle", too. However, only very few people are using it:

9179 messages in total
8935 messages were sent  to 97%
 276 messages were sent  to  3%
   6 messages were BCCed to

If you want to make sure that only is known as a mailing list address then you must type in the complete address, of course. (hint hint hint)

MailList Maintenance - Reply-To Munging is BAD!

Some maillists add a Reply-To: header which points back to the maillist. This feature is supposed to make it easier for its members to reply to the list.

There are several reasons for adding "Reply-To: LIST":

While this additional header indeed does solve a problem with bad mailers and with users, it also creates other problems.

One of these problems is that the RT-enforcing mailers do not give the user an option to reply to the sender in private. Such mailers are broken and should not be used until they get fixed. (Example: Old versions of elm, eg elm-2.4).

Multiple Reply-To

A Reply-To line is used for directing answers to a different address. So, if you are sending your mail from address A but you wish to receive replies at address B then you send to the list at address L like this:
        From:     A (me)
        To:       L (list)
        Reply-To: B (me)
Now, the manager adds another Reply-To line, pointing back at the list:

        From:     A (me)
        To:       L (list)
        Reply-To: B (me)
        Reply-To: L (list)
This is where confusion starts. Some mailers pick the first Reply-To line they find in the header. Others scan the whole header and let the last Reply-To "win". So, depending on your mailer, you will get different results when you "reply".

And it gets worse from there: Suppose that someone sends a mail to two maillist together with a Reply-To pointing back at *both* lists. You will then see a copy on both maillists - but with different additional Reply-To lines:

        From:     A  (me)
        To:       L1 (list1), L2 (list2)
        Reply-To: L1 (list1), L2 (list2)
        Reply-To: L1 (list1)
Now - what will happen when you "reply" to this mail with your mailer? Do you know?

New Requests sent as Answers

Another side-effect of open lists with Reply-To munging is that people send to the list by replying to some arbitrary mail. It is simply soooo convenient to send a message to a list that way.

MailList Maintenance - Subject Munging is BAD!

Some managers add the name of the maillist to the Subject line. This is supposed to make life easier for mailers with an integrated filter, as some people want to sort their mails by 'Subject:'.

Some people want to "sort" the mails by Subject line.

        Subject: linux-l:
Just as with the Reply-To Munging you run into trouble when you send a mail to two maillists:
       list1:  Subject: [list1] new subject

       list2:  Subject: [list2] new subject
Together with a Reply-To to both lists you will get to see mails which cross the additional maillist name:
        Subject: [list1] [list2] [list1] [list2] Re: ...
Subject: linux-l: linux-l-announce: BeLUG: Treffen am 23.08.2000 um 18:00
In the end you get a lot of extra traffic with Subject lines such as these:
        Subject: [list2] make it STOP!!!
                     [list1] cut it out!
                     [list2] what is list1?
                     [list1] list2?
In fact, the Subject lines are usually harder to read than that...

Filter your Mails!

Some mail clients have a builtin filter. However, it is better to use an external mail filter which filters mail independently of your mailer, simply because it makes maintainance easier for you.

This may not make sense to you if you never want to use anything but the programs you are currently using. However, it pays off once you want to try a better mailer as you don't need to adjust all your filter rules.

Besides, most mailing lists can be identified by the address that you send to - so a mail filter makes Subject munging superfluous.

"procmail" is a well know and powerful mail filter. Unfortunately, its "language" seems to be strange at first:

        * ^
This "filter rule" simply checks whether linux-l@ is included in any of the "To" lines known (ie it checks Cc: and other lines, too) - and then saves the result in the folder "LINUX".

Actually, you can send mail to this very very special mailing list at two addresses which only differ in the hostname:
But there is no need to define two rules now. As procmail makes use of regular expressions, this allows for powerful use of "patterns". So it is quite simple to tell procmail that "either 'calle' or 'mlists' is a valid match":

        * ^TOlinux-l@(calle|mlists)
And just case "linux" is allowed, too, you can make the suffic "-l" optional:
        * ^TOlinux(-l)?@(calle|mlists)
So, this is all quite simple, isn't it? :-)

Try this with a mailer which features a builtin filter!

For more examples see Sven's setup for procmail and the manual to procmailrc.

MailList - Subject De-Munging with Procmail

Here is a recipe which de-munges munged mailing lists. (Try to say that three times really fast. ;-)


* LIST ?? .
    SUBJECT=`formail -zx Subject:`
    :0 f
    | formail -i "Subject: `echo ${SUBJECT} | sed -e \"s/\[${LIST}\] *//\"`" \
              -i "X-Label: ${LIST}"
Procmail recipe by David Champion - thanks! :-)

MailList - MailList Signature

Some managers add their own signatures with additional information, eg the maillist's homepage address and commands for unsubscribing.

Again, the main idea is good: Additional information in every message to prevent subscribers from asking the bleeding obvious.

        MailList HomePage:
        MailList Unsubscribe:  echo unsubscribe |
However, this additional information also adds a lot of noise to the list. Especially because there are so many people who quote everything but hardly delete anything of the quoted material - and this usually includes the maillist signature.

What's worse - the additional signature conflicts with the signatures of the sender of the message. One more reason not to use a maillist signature!

MailList - Personal Signatures

MailList - Business Signatures

Many people set up their mailer at work to add info about the company, such as the snail mail address, their building name, room number, phone and fax numbers.

while this is fine for some emails it certainly is almost always redundant on mailing lists.

moreover, the reader will think that everything you say you are saying for your company. this is bad - especially when you get yourself into a heated debate which involves name calling.

AVOID business signatures on emails!

most mailers cannot be adjusted to distinguish between personal mail, business mail, and mailing lists. but you can always delete the signature. and if you mailer does not show you the signature it will append, well, time to get a mailer which does that.

MailList - Company Disclaimers

Some companies automatically add a disclaimer to every outgoing message. some are small - many add several lines, and some are outrageously huge.

see this page for examples:

People tell me they hate the disclaimers - but they cannot do anything because the legal department has decided on this and has instructed the postmaster to adjust the mail host for adding those.

The legal departments should get a clue to not mess with messages!

are you fed up about those disclaimers? then send me an email - and i'll add your company's disclaimer to the page.

of course, you can use your mailer's signature to append a text like this:

please apologize the huge disclaimer.
the legal department made us do it..


Threading is a feature of mailers and newsreaders to collect all messages which are replies to a post.

[TODO: Add screenshot of threaded index for mutt and slrn.]

Threading is only possible when answers contain a reference to the previous message. However, a reference to some included information is never a good idea (message content can be sent more than once and can even be empty). Therefore each message gets an extra header line with a unique "message identification":

        Message-ID: <>
And answers reference this Message-ID with either of these lines:
        In-Reply-To: MID

        References:  MID1 MID2 MID3 ...
So these lines are necessary for threading to work.

Summary: Please use mailers which give reference to the previous message. Using bad software will cause problems for others. Do not use it. Do not install it, either!

Mutt is *one* of the mailers which are capable of "threading". Unfortunately there are not many other mailers which feature this. But I am still hoping that bad software will eventually die...

HOWTO Attach Data/Files

Using MIME to "attach" files are a nice way to separate a message. However, there are so many broken mailers which do not support MIME properly that it addsd a lot of noise to maillists.

Please - do not attach big files. Keep attachments small!

Especially on development maillists there a lot of attached patches. If it's small - fine. If it's big then please make your patch available on WWW and simply add its address. Thankyou!

And if you *have* to attach files then you should add some info on them. More on this is in the

  • HOWTO Send Attachments FAQ

    Autoresponders / Vacation

    Some folks go holidays and set up a "vacation" mail saying they are not available. The idea is nice but is a PITA for mailing lists with "Reply-To: LIST" as they will automatically send a reply to almost every mail they receive.

    So - before you leave town - adjust your mail filter!!

    Message Content

    From: - do not send from work
    Do not use your work address to send mails to mailing lists - unless it is an internal mailing list at work, of course.
    "But it's the only address I've got."
    Is it your job to follow mailing lists at work? If not, then DONT DO IT.
    There are a lot of sites who offer free addresses. Get yourself such an address and use it for maillists. Then you can send to the maillist as, say, "me@freeaddress":
        From:     me@freeaddress
        To:       MailList
    And if your mailer does not allow you to send as "me@freeaddress" then you must send it via the mail service of the freeaddress site.


    There are two kinds of signatures:
    1. Informal Signatures
    2. Digital Signatures
    Informal signatures are simply information which are appended to every message. Please keep this short! The recommended limit is four lines - each having at most 80 characters.

    Digital signatures are additional information which are used for authentication, ie to verify that the message was sent by some person. This can add quite some data which distracts the reader.

    A few mailers have "support for PGP" (or other kinds of digital signatures), so they can hide the additional information from view when displaying a message. However, you cannot expect readers to appreciate digital signatures when they can usually believe the contents on a mailing list.

    So, please do not use digital signature on maillists - unless you have a good reason for doing so!

    By the way, "Digital signature are cool" is *not* a good reason for using them.

    HOWTO Write Bug Reports

    Follow these steps:
    GOAL:       What was your goal? What did you intend to do?
    Action:     Which commands did you give?
    Expectation:    What did you expect will happen?
    Effects:    What happened?  Were there any error messages?
            Were there any effetcs on hardware?
    Errors:     Which error message did you get?
            Can you reproduce the error?
    Help:       Did you use the latest version of the software?
            Did you read the documentation (FAQ, HOWTO, manual)?
            Did you contact your system administrator?
            Did you ask on a mailing list yet?
            Did you ask on a newsgroup yet?
            Are you able to locate the bug in the code?
            Can you suggest a bug fix?
            Do you have a patch?
    What to include in the error report:
  • OS version ("uname -a")
  • Program versions ("vim --version")
  • Error Messages (copy&paste)
  • Example:
    OS:  SunOS ritz 5.6 Generic_105181-17 sun4u sparc SUNW,Ultra-250
    version: VIM - Vi IMproved 5.7 (2000 Jun 24, compiled Jun 26 2000 19:09:11)
         Compiled by guckes@ritz, with (+) or without (-):
    The situation:
    I log in to a SunOS 5.6 machine with zsh-3.1.9 as login shell and TERM=linux.
    When I start screen-3.9.8 and vim-5.7 within it without any setup file
    ["vim -u NONE"] then ":edit foo.html" and ":syntax on"
    I expect the file to be colorized - but it is not.
    My question:
    Is there a problem with screen-3.9.8 vs vim-5.7?

    Members - HOWTO Start a Thread

    A "thread" ("mail thread") is the set of mails referring to a mail or sequence of mails which refers to a given mail.

    Avoid Noise! Ask yourself: "Do I really need to post my message on this mailing list?" Please avoid asking the questions which have been asked before. This usually requires an archive with a search engine. Not every list or newsgroup has such an archive, of course. So try to find resources first. Starting a thread requires you to read up on the available material first. If you don't do that then you risk being "flamed", or worse, getting kicked off the list.

    Read the available documentation (FAQs, HOWTOs, Readmes, webpages). If you don't know where to start then just say so! Do not expect ro receive personal replies but be ready to read the responses on the list!

    Do not start be replying! People are lazy. So when the Reply-To points back at the list they just reply to any mail to post to the list. This is bad for several reasons. First, it shows that you are too lazy to start a new thread properly. Second, your message will sorted in with the other, possibly unlrelated emails which screws up the archive, too. Third, you are casing unnecessary confusion. So don't be a jerk and do it properly!

    Subject: Use a subject line that reflects the topic you will talk about. Some mailers ask you to supply the Subject: line before even starting the editor. Just enter something - you will be able to change the Subject: line later before sending off the message. Remember: Messages with an empty Subject: line usually get "scored" down or even deleted as it is possibly "spam".

    Summary:: Make a short summary at the beginning. Go into detail later.

    Hardware/Software: If you talk about computer related subjects then you should include info about your hardware&software with all version numbers and configurations necessary to explain a problem.

    Reply-To:: Set the "Reply-To:" line to your address so that replies will go to you first. Make sure the return address is valid (by sending yourself a mail or whatever.)

    Pictures and other large data: Avoid large data! If you have the possibility to upload data onto a webserver then you should do so and simply include the data's *address* in your message. That way only those who really want to see that data will get it.

    PS: A HOWTO on starting a *threat* is available on page


    Members - HOWTO Answer Requests

    Answering messages with requests is a form of art!

    Reply at all? Avoid unnecessary replies. Ask yourself: Can I really help this person with my answer? Will the other people on this list benefit from reading this? Is there someone else who can give a better explanation?

    Subject:: Again, use the Subject: line! Don't leave it empty!

    Subject: Re:_: A proper subject line for the response to "Subject: foo" is "Re: foo", ie with "Re:_" added at the start. If there already was a "Re:_" at the beginning of the subject line then no further "Re:_" is added.

    BAD Re:_: Some mailers add their own kind of indentation (localized forms of "Re:_" for example). This is BAD! Please adjust your mailer!

    Subject: bar (was: foo) If you think that the Subject: line needs to be changed to reflect the contents of your reply then you might want to show this by including the old subject line. Do this by adding "was:_" before the old subject and put it all into parentheses. Example:

        Subject: maillist etiquette (was: maillist morons)

    Attribution: Attribute each quoted text - so everyone knows who said what. Include the email address of the person who started the thread! If you think that the person who originally asked the question is not a member of the mailing list then (optionally) send him a copy of your answer, so that he will see your answer without having to search the maillist archives for answers.

    Avoid cascades! Avoid many levels of quoted text - known as "cascading". Cascaded text is harder to read. It slows down the reader.

    Stick to the subject! Stick to the subject - only answer the question. Now - this is not easy. It eventually requires you to delete some of what you have written. If you have to add a remark then you might want to mark it as such:

    OffTopic:  Your quoting sucks.  And your signature is too long.

    Quote the question: Quote only what's necessary - if only to repeat the question. Delete the unnecessary. You might want to make a deletion visible by replacing it with ellipsis, eg ".." for short text or "[...]" for longer text.

    Quote Indentation: Use "> " (greater-than and a space) for quoting. Many programs check the start of lines for this to recognize quoted text and to allow for reformatting. Do not use anything else. thankyou!

    Links: Include additional info (e.g. pointers) etc at the end.

    Informal Be informal - avoid bad language, flame wars, personal opinions, signatures. Give ideas, examples, and links instead.

    Text Width: Many people are still using terminals to read mesasges. These mostly have a width of 80 characters per line. So adjust your text for a maximum of "80 chars / line". Most editors allow to set a maximum.

    Paragraphs: Avoid long paragraphs. Structure your text. Paragraphs of four to six lines is usually best for reading.

    Signature: Adding a signature is a nice way to identify yourself. Put your name and address first, optionally add a web address. [Everything else you can put onto that webpage!] But keep it within the accepted maximum is four lines by 80 chars per line. As long as everything is within the 4x80 box noone should complain.

    Members - HOWTO Write a Summary

    A lot of good answers are lost forever because noone ever thought about archiving them. Many mailing lists are hosted on servers now which also have an "archive" and thus allow for "data mining".

    So - please give some feedback to the mailing list even if only to say that you have received responses and that you are evaluating them.

    Better yet, send a summary! But note that a summary is NOT the concatenation of all responses! For a good summary you should edit the responses. Throw away unnecessary information. If necessary, completely rewrite the answers and build a list of pointers, etc. You need not give credits for everything little detail. However, if you want to give credit, then you should mention the names together with the email addresses of the persons.

    I suggest sending a summary to a friend and discuss it with him first. Maybe the maintainer of the mailing list or a "regular" can help you, too.

    HOWTO Maintain a Mailing List

    Unsubscribing Users: Addresses which bounce back the messages should be unsubscribed as they might send back messages to the list. This includes addresses/people who set an automatic "vacation message" back to the list. Some maillist managers allow configuration for automatic handling.

    "unsubscribe" posts: Most maillists allow unsubscription by sending an (empty) mail to a special address (eg "maillistname-unsubscribe@domain") or by sending a "command" to an address ("echo subscribe | mail majordomo@domain"). However, user stend to forget how this works and thus send their unsubscription request to the mailing list. This is quite annoying.

    In this case the maillist maintainer should send a reply to the list saying that he will deal with this problem. This should shut up others to deal with this on the maillist. Then he should unsubscribe the address; the maillist manager should then send a conformation message to that address. Optionally, you should contact the person personally.

    Common Problems with Mailers

    Most mailers have only one command for replying to a mail. Such a reply will go to the address in the From: line - or to the address in the Reply-To: line - if it exists.

    Mailing lists try to make it easy to respond to the list by adding a Reply-To: line with the address of the maillist; so a reply to such a mail goes back to the mailing list. (see Reply-To Munging).

    So mailers really need *two* commands - one command to reply to the sender (the usual "reply") - and another command which replies to the mailing list address ("list-reply").

    Do you know more mailers with a "list-reply" command? Let me know!

    The Group-Reply Problem

    Now, some mailers have a command that replies to "all recipients" (commonly know as "group-reply"). This command is *not* a solution to the problem as this will accumulate additional addresses which might already be subscribed to the list, thus sending them all duplicate copies (aka "dupes) of the message.

    Here's what happens:

    The initial message is from some sender with address 'A' ("From: A") and goes to the list ("To: L"):

        From: A
        To:   L
    Now, when someone else ('B') group-replies to this message the header looks like this:

        From: B
        To:   L
        Cc:   A
    And with C group-replying you'll get this:

        From: C
        To:   L
        Cc:   A,B
    Guess what happens after D, E, and F have group-replied, too?!


        From: F
        To:   L
        Cc:   A,B,C,D,E
    As you can see, "group-reply" is *not* a good solution for this. Your mailer needs "list-reply"!

    And, no, Mozilla (Netscape's Mailer) and Outlook dont have that.

    Open vs Closed Maillists

    An "open maillist" requires no subscription for sending - the incoming mails will be distributed even when the sender is not subscribed to the list.

    This openness brings one problem: You cannot tell whether the sender is or is not a susbcriber to the list. Therefore it is not clear whether your reply to the list will be distributed to the sender. The "solution" would be to "reply to all" - just in case the sender is not a member of the list. However, if he is a member of the list then he will get your reply twice. This can be quite annoying - especially if the amount of data sent is huge. And it will lead to the group-reply problem.

    The other "solution" is to use the Reply-To line to redirect responses. However, this can clash with mailing lists which add a Reply-To line that points back at the least (see Reply-To Munging).

    And even with an open maillist, no Reply-To Munging, and users who all use mailer which can "list-reply", adding a Reply-To line will just work for direct replies; all further replies will not be copied back to the sender, of course. if this is wanted by the sender then he should simply subscribe himself to the list, right?

    Automatic Replies

    WARNING! Do *not* send automatic replies to mailing lists!

    Many people activate some kind of "auto-reply" mechanism when they leave their bureau - forgetting that they are subscribed to mailing lists. The effect is that they will be sending replies to the mailing lists automatically - and thus annoy their fellow maillist folks.. :-(

    The worst case is when an auto-reply account sends replies to another auto-reply account - then they will send mails between them, accumulating tons of emails. :-(

    My advice is to not send auto-replies at all. It avoids lots of problems..


    A public response to a public message. Note: Public responses to private messages are frowned upon.

    A not-so-smart user. Sounds like "loser".

    Short for "mail program". The technical term is "Mail User Agent" (MUA).

    Abbreviation for "mailing list".

    Short for "mailing list manager". This is the program that manages the distribution of the mails to the subscribers.

    Message is the general name for the things you send with Email and News/Usenet. Emails sends "mails" and on News/Usenet you "post" an "article"; you either "followup" to an article in public by posting a new article or you answer in private by "replying" to an article by Email. You usually include some cited material from the previous message to keep some context.

    Abbreviation for "mail delivery agent".
    Examples: sendmail, tmail, procmail.

    Abbreviation for "mail transfer/transport agent".
    Examples: sendmail, exim, qmail, smail, postfix.

    Abbreviation for "mail user agent".
    Examples: elm, elmme+, mutt, pine.

    "open list"
    An "open list" accepts mails from unsubscribed senders.

    An answer to a message - usually an Email.

    Messages with ads - usually sent without request. Also known as: Unsolicited Commercial Email (UCE).

    A person subscribing to a maillist. Actually this is just an address. A person could subscribe to a maillist multiple times under various addresses, of course.


    "Man's best friend."
    "All mail clients suck. But mutt sucks less."

    Message Editing and Quoting Guide (with Examples)

    Reply-To munging considered harmful [..,990831,010304]
    Author: Chip Rosenthal (German)

    Reply-To Munging Considered Useful [990831]
    Author: Simon Hill

    Sven's page on Email

    Hinweise zur LUG-Mailingliste LUG-OWL [000811]
    Hints for sending messages to a Linux User Group mailing list. In German.

    Emily Postnews
    Emily Post News.
    A satirical way of describing etiquette for "posts" on "Usenet". A classic!

    MY Mailing List

    MY setup for MY "perfect" mailing list. Disagree all you want. ;-)


    HOWTO Maintain Mailing Lists:

    A remark on bad mailers: I keep getting email from people telling me that their boss, wife (or both) forces them to use a mailer which does not allow for easy editing of quoted text or text in general - and that therefore they do not care about editing their emails. Well, I tell them that sending full quotes is not necessary - no matter how crappy the mailer is. There is no need to impose your problem with editing on others by not editing your mail at all. You can get better mailers - so get them. Some really good one are actually available for FREE. So - no excuses. Whatever software you use - it is up to *you*! Everyone deserves the software he uses.

    Created:     Mon May 22 12:00:00 MET DST 2000
    Send feedback on this page to
    Sven Guckes