The mailing list for listmasters using Sympa

[Marco Gaiarin <address@concealed>]

We have a sympa instance that own an announcement list, that have some
thounsand subscribers, and is used by a not-so-skilled user to send some
sort of newsletter.

Last week the user sent a message, the server itself or the SMTP servers on
the back was busy, so the message does not come back instantly, and the user
resend it. And resend it. 5 times. ;(
Clearly, does not ''bounce'' the message, but compose a new message (so,
different msgid) with the exact same content. ;(

Before sympa we used smartlist, and on smartlist we do something like that:

 # where the md5 checksums go
 md5sums=md5sum.cache

   # scan only the body and compute md5sum on the body,
   # after first removing all newlines and non-alphabetic chars
   # and making everything lowercase
 :0 b
 MD5SUM=| /usr/bin/sed -e 's/^--.*//g' \
       | /usr/bin/tr -d '\n' \
       | /usr/bin/tr '[:upper:]' '[:lower:]' \
       | /usr/bin/sed -e 's/[^a-zA-Z]//g' \
       | /usr/bin/md5sum

   # lock $md5sums
 LOCKFILE=$md5sums.lock

   # see if this is a duplicate message
   # if fgrep succeeds, we've tossed the mail
 :0 aWhi
 | /bin/fgrep -s "$MD5SUM" $md5sums

   # Hurray! The mail is not a duplicate!
   # add the new checksum to the file and keep the last 1000 md5sums
 :0 echi
 | ( /usr/bin/tail -1000 $md5sums; /bin/echo "$MD5SUM" ) > $md5sums.new; \
    /bin/mv $md5sums.new $md5sums

   # unlock $md5sums
 rm -f $LOCKFILE

it was a crude hack, but works.


There's something similar in sympa, or what is the best way to implement
that hack?


Thanks.

-- 
  tutti chiusi in tante celle fanno a chi parla piu' forte
  per non dir che stelle e morte fan paura              (F. Guccini)