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=< br...@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 _______________________________________________ Mailman-users mailing list -- mailman-users@mailman3.org To unsubscribe send an email to mailman-users-le...@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/32GMLRDG3QFRVT2IC76KY7ND5K4EQ5C2/ This message sent to arch...@mail-archive.com