[Mailman-Users] External processing failed. communigate and mailman

Mark Sapiro mark at msapiro.net
Wed Apr 6 02:26:01 CEST 2011

On 4/5/2011 11:49 AM, Ch Abarguia wrote:
> N.B. Sorry if it's a duplicate post. I didn't receive the message I
> sent to the list. Probably because it was done before I change from
> digest to single.

There are two reasons why you didn't see your original post. First, you
are sending from gmail and you will never see your own posts because
gmail discards them as duplicates of the sent message. See the FAQ at

The other reason is in this case, you are a new member of the list and
new members are moderated by default, and anti spam measure, so your
post had to wait for moderator approval.

> Installed mailman 2.1.13, via macports, on snow leopard ( 10.6.7)
> with success. Same results following the procedure Larry Stone
> described on 
> http://www.mail-archive.com/mailman-users@python.org/msg56923.html
> Everything is working fine except for the integration with
> communigate. Error message from communigate : failed on 'mailman post
> testlist at domain.com'. Error Code=external processing failed
> ( pathname of the wrapper : /opt/local/libexec/mailman/mail )

I know nothing of communigate and little specific about Apple, but the
pathname of the mail wrapper should probably be
/opt/local/libexec/mailman/mail/mailman -
/opt/local/libexec/mailman/mail would normally be the directory that
holds the wrapper.

> The answer from the communicate discussion list is :
> " Make sure that your program reads everything from the standard
> input up to EOF, exits with zero status code and does not output to
> the STDERR stream."
> Extract from the communicate documentation : "The message text
> (including the message headers and the message body) is passed to the
> external application as its standard input. 
Note: the application
> must read the entire stdin data stream, otherwise message processing
> fails. When the external application completes, the PIPE module reads
> and discards the application standard output. Make sure that your
> application does not write anything to its standard output, so it is
> not blocked when the communication channel (pipe) buffer between the
> application and the Server is full."
> Thanks in advance for any help and hints to use mailman with
> communigate.

Also, the post command to the wrapper should normally be

   wrapper post listname

I.e., in this case

  mailman post testlist


  mailman post testlist at domain.com

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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