[exim] Possible DKIM issue query

Hi all,

For the past 2 or so weeks I've noticed that the emails coming from
sendgrid servers are being sent to me over and over again.

The only issue I can see on my side is this line cropping up in my logs:


PDKIM: d=sendgrid.com s=s1 [failed key import]


I've been in contact with sendgrid and they say they are seeing defers
coming from me however I'm seeing the message delivered


What could be going wrong here?

When I look up the DNS results myself the DKIM for this (
s1._domainkey.sendgrid.com ) is actually a CNAME to
s1.domainkey.u7715623.wl124.sendgrid.net.

The final result is the TXT record you'd expect however the record
itself is missing the "v=DKIM1" field.

I'm also seeing something similar with this one too:

PDKIM: d=email.currys.co.uk s=dixonsretail [failed key import]


Is it the fact I'm getting CNAME's back instead of a TXT causing this to
fail or is it the lack of the V field or something else I'm missing ?

Is there something I can do to turn off the defer I'm apparently sending
back or to turn down the dkim check on incoming messages ?

Running Exim version 4.92 #3 built 24-Aug-2022 16:23:44, Currently on
Debian Buster



Thanks in advance
-d