Reminder emails not coming through iCloud.

I am not receiving reminder emails from American Greetings. I have contacted AG, only to be told it is an iCloud issue. I use Gmail then forward to my iCloud. I receive all of emails from AG as well as all my other Gmail. I see that Gmail receives the AG reminders and forwards them to iCloud but I do not see them as they are not sent on to my Apple Mail. When I go into iCloud this is the the message attached to the reminder:

"The response from the remote server was:

550 5.7.1 Your message from americangreetings.com rejected due to its DMARC policy. See https://support.apple.com/en-us/HT204137 for info. Error code: 355.

Final-Recipient: rfc822; cjgaither1@icloud.com

Action: failed

Status: 5.7.1

Remote-MTA: dns; mx5.mail.icloud.com. (17.178.97.78, the server for the domain icloud.com.)

Diagnostic-Code: smtp; 550 5.7.1 Your message from americangreetings.com rejected due to its DMARC policy. See https://support.apple.com/en-us/HT204137 for info. Error code: 355.

Last-Attempt-Date: Mon, 26 Feb 2018 01:03:41 -0800 (PST)"

Client IP : 47.187.1.47