https://techcommunity.microsoft.com/discussions/exchange_general/exchange-2019-ipblocklistprovider-block-e-mail-even-not-in-blocklist/1557957
exchange 2019 ipblocklistprovider block e-mail even not in blocklist | Microsoft Community Hub
hello guys , i'm facing a prblem on exchange 2019 CU3 . i set the ipblocklistprovider as zen.spamhaus.org to prevent spam e-mails , but some...