[Mailman-Users] mailman and group mismatch error

Mark Sapiro mark at msapiro.net
Mon Aug 3 16:43:52 CEST 2009

Greg White wrote:
>> Mark wrote:
>>> Greg White wrote:
>>>To send the test message I sshd into my box as user, su - to root, and
>>># /usr/lib/mailman/mail/mailman post test
>>>Group mismatch error. Mailman expected the mail wrapper script to be
>>>executed as one of the following groups:
>>>[mail, postfix, mailman, nobody, daemon],
>>>but the system's mail server executed the mail script as group:
>>>Try tweaking the mail server to run the script as one of these groups:
>>>[mail, postfix, mailman, nobody, daemon],
>>>or re-run configure providing the command line option:
>> As I said in an earlier post, this means nothing. It only says that
>> root can't run the wrapper, but says nothing about Postfix running the
>> wrapper.
>If this means nothing then way is it displayed?  It is a worrysome message for the first time maillist admin.

It is displayed because you ran the wrapper from the command line as
root and root's group is not allowed to run the wrapper.

It means nothing because that is not how mail is delivered to Mailman.
Mail is delivered by the MTA executing the wrapper, so the only
meaningful test is to run the wrapper as the same group that the MTA
runs it.

>> How is mutt delivering mail? In your log excerpt I only see
>>>Aug 1 13:21:44 list postfix/postfix-script: starting the Postfix mail
>>>Aug 1 13:21:44 list postfix/master[2494]: daemon started -- version
>2.3.3, configuration /etc/postfix
>>>Aug 1 13:22:23 list Mailman mail-wrapper: Group mismatch error.
>Mailman expected the mail wrapper script to be executed as one of the following
>groups: [mail, postfix, mailman, nobody, daemon], but the system's mail server
>executed the mail script as group: "root". Try tweaking the mail
>server to run the script as one of these groups: [mail, postfix, mailman,
>nobody, daemon], or re-run configure providing the command line option:
>> I see nothing preceding this that indicates Postfix received the mail
>> and tried to pipe it to the wrapper. I only see over two minutes later

And as I said in a follow-up post and LuKreme said in a reply, the
above log message was logged by the wrapper when you ran it by hand as

>>>Aug 1 13:25:01 list postfix/pickup[2498]: C122C8604E0: uid=41 from=
>>>Aug 1 13:25:01 list postfix/cleanup[2767]: C122C8604E0: message-id=
>>>Aug 1 13:25:01 list postfix/qmgr[2499]: C122C8604E0: from=, size=625,
>nrcpt=1 (queue active)
>>>Aug 1 13:25:02 list postfix/local[2769]: C122C8604E0: to=, orig_to=,
>relay=local, delay=0.51, delays=0.25/0.05/0/0.21, dsn=2.0.0, status=sent
>>(delivered to command: /usr/lib/mailman/mail/mailman post mailman)
>>>Aug 1 13:25:02 list postfix/qmgr[2499]: C122C8604E0: removed
>> Which looks like a successful delivery to me. Is Mailman running? Is
>> this message in qfiles/in? What happened to it?
>No there are no mailman aliases in the /etc/aliases file.  Mutt should be using the local postfix server to send the message.  I checked /etc/Muttrc and there is no setting for smtp.

And mutt is delivering to Postfix and Postfix is successfully
delivering to Mailman per the above.

>Mailman is running.  Logging in as root and doing:
># su mailman /usr/lib/mailman/mail/mailman post test
>This account is currently not available.
># sudo -u mailman /usr/lib/mailman/mail/mailman post test
>The system just sits there and does nothing.

It's reading your message from stdin which is your terminal. So no
group mismatch.

>There is only 1 account
>signed up for the mail list so it should take 10 minutes to do something. 
>It has been 10 minutes since I pressed enter and nothing has happened.  I waited 30 minutes and pressed Ctrl-C.  This is what I saw:Traceback (most recent call last):
>  File "/usr/lib/mailman/scripts/post", line 69, in ?
>    main()
>  File "/usr/lib/mailman/scripts/post", line 62, in main
>    inq.enqueue(sys.stdin.read(),
>How am I supposed to post to the maillist if I can't do it from root or a user
>account.  I can't login into the system as mailman:

You are successfully posting to Mailman from mutt. You could also
successfully post from the command line via

sudo -u mailman /usr/lib/mailman/mail/mailman post test < file

where file contains your email message with headers and body, or by
doing what you did and then typing the headers and body of the message
followed by control-D.

I'm not saying you don't have a delivery problem somewhere, but it is
not a group mismatch and it is not a Postfix issue. it is somewhere
beyond that. The message you posted with mutt got to Mailman's 'in'
queue. You need to start looking for what happened after that. Read
the FAQ at <http://wiki.list.org/x/A4E9>.

>The following is everything from the /var/log/maillog since I turn the PC on
>this morning:
>Aug  3 08:24:18 list postfix/postfix-script: starting the Postfix mail
>Aug  3 08:24:18 list postfix/master[2468]: daemon started -- version
>2.3.3, configuration /etc/postfix
>Aug  3 08:25:02 list postfix/pickup[2472]: 38DFD8604E0: uid=41
>Aug  3 08:25:02 list postfix/cleanup[2711]: 38DFD8604E0:
>Aug  3 08:25:02 list postfix/qmgr[2473]: 38DFD8604E0:
>size=625, nrcpt=1 (queue active)
>Aug  3 08:25:02 list postfix/local[2713]: 38DFD8604E0:
>orig_to=, relay=local, delay=0.56, delays=0.28/0.05/0/0.23,
>dsn=2.0.0, status=sent (delivered to command: /usr/lib/mailman/mail/mailman
>post mailman)

Above is a successful delivery of a post to the 'mailman' list.

>Aug  3 08:25:02 list postfix/qmgr[2473]: 38DFD8604E0: removed
>Aug  3 08:25:03 list postfix/smtpd[2715]: connect from
>>Aug  3 08:25:03 list postfix/smtpd[2715]: BEB718604DD:
>>Aug  3 08:25:03 list postfix/cleanup[2711]: BEB718604DD:
>>Aug  3 08:25:03 list postfix/qmgr[2473]: BEB718604DD:
>>from=, size=1952, nrcpt=1 (queue active)
>>Aug  3 08:25:03 list postfix/smtpd[2715]: disconnect from
>Aug  3 08:25:03 list postfix/local[2713]: BEB718604DD:
>relay=local, delay=0.09, delays=0.01/0/0/0.07, dsn=2.0.0, status=sent
>(delivered to maildir)

And this looks like a successful delivery of some kind of response from
Mailman. What was in this message?

[followed by repeats of the same scenario]

Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan

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