Email sent to a gmail ID got DMARC failed

An user had sent an email to gmail ID and got a report of dmarc failed. Not really sure why this happened (dmarc failed). This is not happening to all the emails which have sent to gmail. Randomly we are seeing such. Has anyone come across such behavior? Any notable issues on this?

Hi Bharath,

If I may ask, are you using a 3rd party sender to send the emails? If that is the case, it is possible that they have a misconfigured SPF record or incorrectly DKIM signing emails.

It is taking the IP address of gmail as sender IP address. Sender IP address should have been the company exchange address.

Interesting. Is it a forwarded email?

no, not a forwarded one.

any detail you can provide about the message, or was it just a standard email?

Sender Domain: []
Sender IP Address:

Received-SPF: pass (mx123[.]antispamcloud[.]com: domain of designates as permitted sender) client-ip=;[@];;

X-SPF-Result: domain of gmail[.]com designates as permitted sender
X-DKIM-Status: none

From the above info, we can see that sender IP address is of and not of my company IP address.

Where is located? that may be the cause.