[Mailman-Users] how senddigests cron are generated & how can I stop it?

[Monia BEN MLOUKA]

Hi,
I've just start to monitor a system which implements mailman, 
and I receive a regular email (every day) from senddigests cron with this body message:

You are not allowed to post to this mailing list, and your message has been automatically rejected.  If you think that your messages are being rejected in error, contact the mailing list owner at mailman-owner at lists.system.com.

There is a traceback attached in the mail :

Traceback (most recent call last):
  File "/usr/lib/mailman/cron/senddigests", line 94, in ?
    main()
  File "/usr/lib/mailman/cron/senddigests", line 86, in main
    mlist.send_digest_now()
  File "/usr/lib/mailman/Mailman/Digester.py", line 60, in send_digest_now
    ToDigest.send_digests(self, mboxfp)
  File "/usr/lib/mailman/Mailman/Handlers/ToDigest.py", line 132, in send_digests
    send_i18n_digests(mlist, mboxfp)
  File "/usr/lib/mailman/Mailman/Handlers/ToDigest.py", line 306, in send_i18n_digests
    msg = scrubber(mlist, msg)
  File "/usr/lib/mailman/Mailman/Handlers/Scrubber.py", line 227, in process
    url = save_attachment(mlist, part, dir, filter_html=False)
  File "/usr/lib/mailman/Mailman/Handlers/Scrubber.py", line 466, in save_attachment
    fp = open(path, 'w')
IOError: [Errno 36] File name too long: '/var/lib/mailman/archives/private/[too long file name].html'

Any ideas about how it's generated and how can I stop it?

Thanks in advance for your help!

Monia