Run the below PowerShell to block the senders address :

foreach ($content in (get-content “D:\blacklist_addresses.csv”)){$temp=(get-transportrule “Blacklist”).From;$temp+=$content;set-transportrule “Blacklist” -From $temp}

Run the below PowerShell to block the senders domain :

foreach ($content in (get-content “D:\blacklist_domain.csv”)){$temp=(get-transportrule “Blacklist Domain”).SenderDomainIs;$temp+=$content;set-transportrule “Blacklist Domain” -SenderDomainIs $temp}