[Solved] This message does not have authentication information or fails to 550-5.7.26 pass authentication checks

Question

That is odd. The sending source IP is definitely in your SPF, and the DMARC record includes aspf=r, so the header from address in a child domain is valid and matches. I’d also note that your DMARC has p=quarantine, but gmail is acting like it’s reject. This is gmail though, so you can’t expect it to behave well.

I expect that the problem is that you don’t have an SPF record set for server.cbs-canon.com, so make sure that exists and allows the same sources as cbs-canon.com. It looks like you’re not doing DKIM signatures either, meaning that both SPF and DKIM are failing, resulting in a DMARC failure. Try adding that DNS record, or redirecting/including server. to your root domain.

Accepted Answer

That is odd. The sending source IP is definitely in your SPF, and the DMARC record includes aspf=r, so the header from address in a child domain is valid and matches. I’d also note that your DMARC has p=quarantine, but gmail is acting like it’s reject. This is gmail though, so you can’t expect it to behave well.

I expect that the problem is that you don’t have an SPF record set for server.cbs-canon.com, so make sure that exists and allows the same sources as cbs-canon.com. It looks like you’re not doing DKIM signatures either, meaning that both SPF and DKIM are failing, resulting in a DMARC failure. Try adding that DNS record, or redirecting/including server. to your root domain.