Hi All,

是這樣的, 我們公司有一台Exchange 2016, 上面有很多群組信箱,
其中一個群組信箱有包含到另外一地同企業的的email, 他們當地是用Gmail服務,

問題來了, 十一月份開始(大約), 部份廠商寄送到Exchange 2016上的Group email,
轉寄到外地公司的Gmail 都被退信, 內容顯示為 [Unauthenticated email from abc.com is not accepted due to domain's DMARC policy.] , 奇怪的是只有轉寄到Gmail的會有問題, 其他非Gmail信箱的mamber都沒有問題, 如果廠商直接寄給Gmail同事卻又可以正常收到, 所以判斷是群組轉寄的問題,

請教各位先進前輩, 單兵該如何處理?
==========狀況更新 12/31=======================
經詢問Google工程師, 說到原寄件者 aaa@abc.com寄信到 bbb@bbb.com再轉寄到 ccc@ccc.com (Gmail), 所以@ccc.com收到的是由 @bbb.com寄過來的信, 但是aaa@abc.com的信件有包含 @abc.com的 DMARC Policy, 所以@ccc.com偵測到一定會錯誤,因為信件不是aaa@abc.com寄過來的...
請問Exchange Group信箱是否能完整不動把信件轉丟到另一方?
而不是用Exchange轉寄...
=======資料更新 2019/1/3==============
203.186.xxx.xxx is bbb.com (our email domain, email group member have ccc.com email box)
203.199.xxx.xxx is abc.com (Sender have DMARC policy)
在GMAIL管理介面看到的信件如果 SMTP server is 203.199.xxx.xxx, SPF check is pass,就可以正常送到Gmail信箱
但如果SMTP server is 203.186.xxx.xxx , SPF check is fail.就會被Reject,
同一封信寄給群組信再轉給Gmail信箱, 部份可以部份不行.
收件SMTP紀錄有時有兩筆(上述兩筆), 就看哪一筆在下面決定Gmail收不收...
真的不懂阿.. 以下為收件紀錄, 一封信一個收件者的訊息.

Jan 2, 2019, 19:12
Received from an SMTP server with IP address: 203.199.xxx.xxx (TLS enabled)
250 2.0.0 OK
Jan 2, 2019, 19:12
Inserted into Gmail delivery pipeline
Jan 2, 2019, 19:12
Delivered to Gmail mailbox
Jan 2, 2019, 19:12
Received from an SMTP server with IP address: 203.186.xxx.xxx (TLS enabled)
550-5.7.1 Unauthenticated email from icicibank.com is not accepted due to 550-5.7.1 domain's DMARC policy. Please contact the administrator of 550-5.7.1 icicibank.com domain if this was a legitimate mail. Please visit 550-5.7.1 https://support.google.com/mail/answer/2451690 to learn about the 550 5.7.1 DMARC initiative.
Jan 2, 2019, 19:12
Rejected