Due to Gmail new rule mail "Delivery Failed happening often/

We are using routing email function.

Routing from our domain to Gmail.

But recently, Due to Gmail spam mail new rule starting from Feb/2024, Some customer’s mail doesn’t deliver.

They are not setting “DKIM DMARK SPF” properly,

It become “Delivery Failed”.

We can’t say all customer to set DMARK.
To solve this problem, Is there any solution?

What exactly does the Activity Log say, when you expand each “Delivery Failed” item?

Unless you’re willing to share it all, then at least the long message under “Rejected reason:”.

Is the status on your Activity Log saying none", “fail”, … or what exactly?

At least the full “Rejected reason:” message would be beneficial in order to come with suggestions.

However, based on the information shared so far, - it sounds like the only solution would be to drop Gmail, and find somewhere else to be the destination for your Email Routing activities, if you want to receive messages that are failing email authentication, as it sounds like you’re indicating.

In addition, if you’re going to look for another provider, you would like to avoid any free mail provider out there, as they are literally all going in such directions.