Sameer 2 Posted March 16, 2021 Share Posted March 16, 2021 Third party email gateway (on-prem) huge email Q with deferred message 451 4.7.1 ------ > MS Exchange 2016 (running on-prem Windows Server 2016) -----> ESET for Exchange 7.3.10011.0 (default setup) : any suggestion as to how to resolve this issue as am new to emsx Link to comment Share on other sites More sharing options...
ESET Staff M.K. 17 Posted March 16, 2021 ESET Staff Share Posted March 16, 2021 Hi, ESET Mail Security for Exchange uses '451 4.7.1 Please try again later' response for greylisted messages, but Greylisting is turned off by default. Have you checked in-product logs or transaction logs to verify whether messages were rejected by Mail Security? Link to comment Share on other sites More sharing options...
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