Re: [OFF]: DKIM broken by certain email clients

[James Brown]

On 25/09/2008, at 12:01 AM, Wietse Venema wrote:

James Brown:

The flow of my email is:

Mail.app -> ASSP -> Postfix -> amavisd-new -> Postfix -> Astaro
Gateway -> Internet

I think :-)

Your mail is modified AFTER the DKIM signature is computed. Therefore,
the source of the message not breaking the signature.

However, you can use this source to send the same test message
repeatedly, and to find out what your email looks like at different
points AFTER it is signed. This will reveal what is making the
change that breaks the DKIM signature.

        Wietse

Thanks Wietse.



My master.cf ends with:

tlsmgr    unix  -       -       n       1000?   1       tlsmgr
retry     unix  -       -       n       -       -       error
10026     inet  n       -       n       -       -       smtpd
vacation        unix    -       n       n       -       -       pipe

amavisd-new     unix    -       -       n       -       2       smtp
  -o smtp_data_done_timeout=1200s
  -o smtp_send_xforward_command=yes
  -o smtp_tls_note_starttls_offer=no
127.0.0.1:10025 inet n    -       n       -       -     smtpd
    -o content_filter=
    -o smtpd_delay_reject=no
    -o smtpd_client_restrictions=permit_mynetworks,reject
    -o smtpd_helo_restrictions=
    -o smtpd_sender_restrictions=
    -o smtpd_recipient_restrictions=permit_mynetworks,reject
    -o smtpd_data_restrictions=reject_unauth_pipelining
    -o smtpd_end_of_data_restrictions=
    -o smtpd_restriction_classes=
    -o mynetworks=127.0.0.0/8
    -o smtpd_error_sleep_time=0
    -o smtpd_soft_error_limit=1001
    -o smtpd_hard_error_limit=1000
    -o smtpd_client_connection_count_limit=0
    -o smtpd_client_connection_rate_limit=0

    -o local_header_rewrite_clients=
    -o smtpd_milters=
    -o local_recipient_maps=
    -o relay_recipient_maps=

I'll have to look into it more tomorrow.

James.

Astaro is doing the DKIM signing, so if I understand you correctly, my mail flow is not as I described it above. flags=DRhu user=autoresp argv=/Library/WebServer/Documents/ postfixadmin/VIRTUAL_VACATION/vacation.pl -o receive_override_options =no_header_body_checks,no_unknown_recipient_checks,no_milters

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