Alan Wylie's Web Site

Fri, 2018-04-27

I started seeing repeated delivery failure messages from the Linux Kernel Mailing list: permalink

postfix/cleanup[20414]: 2819B22313: info: header Subject: Do You Need A Hand? from[];
opendkim[7694]: too much header data
A quick Google suggested that this was because the header size was greater than the default of 65536 that OpenDKIM accepts. I tried increasing this to 262144, but this didn't help. I then set
On-Security            accept
in opendkim.conf. This caused the mail to be accepted. I then had a look inside the mail:
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=default;

$ grep DKIM-Signature msg.5SAz | wc -l

$ sed -n '1,/^$/p' msg.6SAz | wc -c
What on earth are playing at?