It seem that issue about Domain kiaceramics.com restrict mail delivery from 1 ip address simultaneously for a time to prevent the delivery of spam havn't fixed yet.
In addition, I’ve asked owner of user: cte_esmart@scg.co.th. She told me that amount of mail from this user is dependent on amount of documents that must send to user in kiaceramics.
Could you please provide any update for us or unlimited receive mail from SCG ? Because right now there are many outgoing mail (about 2000 mails) from SCG and SCG Mail Gateway try to reach your domain. So, SCG Mail Gateway currently overload from this issue.