Help! Duplicate DKIM key
Hi all,
I'm having *sudden* issues with our SMTP server (Amazon SES) erroring out while trying to send from our most active Mailman3 mailing list (~1,000 subscribers; modest Mailman3 (v 3.3.3) installation (10+ lists, Ubuntu).
Here is the message. We've got several thousand log entries like this now:
*554 Transaction failed: Duplicate header 'DKIM-Signature'* Mar 10 08:31:10 mail1 postfix/smtp[217753]: 738B53F15E: to=< brian@brianmichaelslaw.com>, relay=xxx.org[44.225.xxx.xx]:587, delay=37, delays=2/35/0.16/0.13, dsn=5.0.0, status=bounced (host said: 554 Transaction failed: Duplicate header 'DKIM-Signature'. (in reply to end of DATA command))
As we don't do any DKIM key signing on the related Postfix machine I've opened up a case with Amazon. However, if there is a troubleshooting I should adopt on this issue with regard to Postfix/Mailman I'd like to know what your recommendations are, or what steps I can follow to better help the vendor ensure that this issue isn't coming from either the Postfix machine or the Mailman machine.
Much thanks,
José Bernal Web/Application Engineer
On 3/11/25 7:06 AM, Jose Bernal via Mailman-users wrote:
Here is the message. We've got several thousand log entries like this now:
*554 Transaction failed: Duplicate header 'DKIM-Signature'* Mar 10 08:31:10 mail1 postfix/smtp[217753]: 738B53F15E: to=< brian@brianmichaelslaw.com>, relay=xxx.org[44.225.xxx.xx]:587, delay=37, delays=2/35/0.16/0.13, dsn=5.0.0, status=bounced (host said: 554 Transaction failed: Duplicate header 'DKIM-Signature'. (in reply to end of DATA command))
This is Amazon SES being stupid, but you can avoid this issue by setting
remove_dkim_headers: yes
in the [mta] section of mailman.cfg.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
Mark - adjusting this setting in mailman.cfg seemed to do the trick. No more errors and postfix is able to send mail out to our Amazon SES relays just fine now.
Thank you,
On Mon, Mar 10, 2025 at 6:57 PM Mark Sapiro <mark@msapiro.net> wrote:
On 3/11/25 7:06 AM, Jose Bernal via Mailman-users wrote:
Here is the message. We've got several thousand log entries like this
now:
*554 Transaction failed: Duplicate header 'DKIM-Signature'* Mar 10 08:31:10 mail1 postfix/smtp[217753]: 738B53F15E: to=< brian@brianmichaelslaw.com>, relay=xxx.org[44.225.xxx.xx]:587, delay=37, delays=2/35/0.16/0.13, dsn=5.0.0, status=bounced (host said: 554 Transaction failed: Duplicate header 'DKIM-Signature'. (in reply to end
of
DATA command))
This is Amazon SES being stupid, but you can avoid this issue by setting
remove_dkim_headers: yesin the
[mta]section ofmailman.cfg.-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
Mailman-users mailing list -- mailman-users@mailman3.org To unsubscribe send an email to mailman-users-leave@mailman3.org https://lists.mailman3.org/mailman3/lists/mailman-users.mailman3.org/ Archived at: https://lists.mailman3.org/archives/list/mailman-users@mailman3.org/message/...
This message sent to jbernal.web.dev@gmail.com
participants (2)
-
Jose Bernal -
Mark Sapiro