Emails bouncing due to "Dkim" failure

[BalooPoo]

I run a fantasy football comp for my group of friends and I'm trying to send the final update for the season, only for it to bounce back with this message:

550: 5.7.515 Access denied, sending domain SKY.COM doesn't meet the required authentication level. The sender's domain in the 5322.From address doesn't meet the authentication requirements defined for the sender. To learn how to fix this see: https://go.microsoft.com/fwlink/p/?linkid=2319303 Spf= Pass , Dkim= Fail , DMARC= Pass

I use the Sky/Yahoo web browser so can't investigate using Outlook, as suggested on the microsoft link.  The message has only bounced back from 9 of my mates, not all 20 of them.  Is this something that Sky/Yahoo need to fix?  Any clues?

[caesarome]

@BalooPoo 

Do you send these emails to all 20 recipients at the same time. If you do are you able to send it to one of these people one at a time to see what happens ?

[Mark39]

---

@BalooPoo wrote:

Is this something that Sky/Yahoo need to fix?  Any clues?

---

I would think so. However I suspect the likelihood of finding someone within Sky who a) knew what was needed, and b) was motivated sufficiently to make the changes required is negligible.

[jayach]

It's odd that some fail, but others don't, as presumably all have the same "from" address. (Your Sky email address)

Do all those that fail have anything in common, such as the same domain? (i.e. all gmail or outlook/hotmail)

[Baloox]

That's a good shout.  It's only the hotmail and outlook addresses that are bouncing back.  gmail is ok, as are company addresses.

I've also tried to send to one hotmail address only, and that bounced back with the same error.

[Mark39]

@Baloox are you the same person as @BalooPoo who started this thread?

[Baloox]

Yes.  For some reason I had to re-register to be able to get into the community again