用gmail作為發件郵箱，gmail無法收到，原因是發過去的郵件顯示xxx主機代發 被拒收 550-7.2.26，谷歌回復說

smtp.gmail.com
465

Reading that message, it looks like you are sending messages through a non-Google server and the return address has the domain tkspades.shop.localdomain.

You need to fix the sending program to use the correct domain and, if possible, add a DKIM signature. (You can have a second DKIM entry with a different selector.)