421 4.7.0 Fortimail closing connection

[armeez88]

Hello colleagues! I am facing the following problem. The client sends me emails, but some are blocked by fortimail with error "421 4.7.0 fortimail.mydomain.com closing connection". That is, four out of five letters arrive normally, one does not. The client has a postfix. Which side is the problem? How can you solve it?

[emnoc]

Did you check to see if the ip.rating or gfreylisting is involved ? Can you white list the sender ip and have them test?

Ken Felix